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Sublime Text 3-Anaconda openCV docstring not working?
Question: I'm using the Anaconda plugin in Sublime Text 3. Everything was working
exactly as I expected. I love Docstring. It worked great and saved me a lot of
time.
But when I tried `import cv2`, cv2 was not on the autoComplete list.
AutoComplete and docstring wouldn't work for anything that is in openCV.
I use Mac, with **Python 3.5.1** and **openCV 3.1.0**. In Anaconda.sublime-
settings, my python interpreter is set as: `"/usr/local/bin/python3.5"` I do
have another Windows with Anaconda plugin installed in ST3, and it worked
fine. I don't really what is going on. Any suggestion?
Answer: This setting is not documented in the default `Anaconda.sublime-settings`
file, but I found it once on the [Anaconda
website](http://damnwidget.github.io/anaconda/anaconda_settings/#toc_5):
`"extra_paths"`. Open your `.sublime-project` file, and add the following:
{
...
"settings": {
"extra_paths":
[
"/usr/local/Cellar/opencv3/3.1.0_3/lib/python3.5/site-packageββs"
]
}
}
or, if you're just using your user `Anaconda.sublime-settings`, just add:
"extra_paths":
[
"/usr/local/Cellar/opencv3/3.1.0_3/lib/python3.5/site-packageββs"
]
This will explicitly tell Anaconda to look there for additional modules.
Hopefully that will do the trick.
|
How to install firefoxdriver webdriver for python3 selenium on ubuntu 16.04?
Question: I installed python3-selenium apt package on Ubuntu 16.04. While installing,
got a message:
Suggested packages:
chromedriver firefoxdriver
The following NEW packages will be installed:
python3-selenium
When I try to run the following python code,
#! /usr/bin/python3.5
from selenium import webdriver
import time
def get_profile():
profile = webdriver.FirefoxProfile()
profile.set_preference("browser.privatebrowsing.autostart", True)
return profile
def main():
browser = webdriver.Firefox(firefox_profile=getProfile())
#browser shall call the URL
browser.get("http://www.google.com")
time.sleep(5)
browser.quit()
if __name__ == "__main__":
main()
I get the following error:
> Traceback (most recent call last): File "./test.py", line 19, in main() File
> "./test.py", line 11, in main browser =
> webdriver.Firefox(firefox_profile=getProfile()) File "/usr/lib/python3/dist-
> packages/selenium/webdriver/firefox /webdriver.py", line 77, in **init**
> self.binary, timeout), File "/usr/lib/python3/dist-
> packages/selenium/webdriver/firefox/extension_connection.py", line 47, in
> **init** self.profile.add_extension() File "/usr/lib/python3/dist-
> packages/selenium/webdriver/firefox/firefox_profile.py", line 91, in
> add_extension self._install_extension(extension) File
> "/usr/lib/python3/dist-
> packages/selenium/webdriver/firefox/firefox_profile.py", line 251, in
> _install_extension compressed_file = zipfile.ZipFile(addon, 'r') File
> "/usr/lib/python3.5/zipfile.py", line 1009, in **init** self.fp =
> io.open(file, filemode) FileNotFoundError: [Errno 2] No such file or
> directory: '/usr/lib /firefoxdriver/webdriver.xpi'
I did searching for packages name firefoxdriver in Ubuntu repositories but
none exist. How do I solve this problem?
Any help with installing the webdrivers appreciated!
Answer: You can either upgrade to 16.10 (it's in yakkety) or you can download the deb
from
[here](http://pk.archive.ubuntu.com/ubuntu/ubuntu/pool/multiverse/s/selenium-
firefoxdriver/) (it works - I tried it). Alternatively you can follow
[these](https://christopher.su/2015/selenium-chromedriver-ubuntu/#selenium-
version) instructions to install by hand (chromedriver but for Firefox it's
the same).
|
cairosvg installed but ImportError
Question: I just installed cairosvg and it seems to have worked. If i try to install
again it says:
> $ pip install cairosvg
> Requirement already satisfied(...)
But if I try to import it in python3, it delivers an ImportError:
> >>>import cairosvg
> Traceback(most recent call last):
> (...)
> ImportError: No Module named 'cairosvg'
Any ideas whats going wrong here? By the way, im trying to convert .svg files
to .png ones, if there is a simpler possibility, feel free to tell me!
Answer: install with pip3:
pip3 install cairosvg
|
Do locally set Cython compiler directives affect one or all functions?
Question: I am working on speeding up some Python/Numpy code with Cython, and am a bit
unclear on the effects of "locally" setting (as defined
[here](http://docs.cython.org/en/latest/src/reference//compilation.html) in
the docs) compiler directives. In my case I'd like to use:
@cython.wraparound (False) #turn off negative indexing
@cython.boundscheck(False) #turn off bounds-checking
I understand that I can globally define this in my `setup.py` file, but I'm
developing for non-Cython users and would like the directives to be obvious
from the `.pyx` file.
If I am writing a `.pyx` file with several functions defined in it, need I
only set these once, or will they only apply to the next function defined? The
reason I ask is that the documentation often says things like "turn off
`boundscheck` for this function," making me wonder whether it only applies to
the next function defined.
In other words, do I need to do this:
import numpy as np
cimport numpy as np
cimport cython
ctypedef np.float64_t DTYPE_FLOAT_t
@cython.wraparound (False) #turn off negative indexing
@cython.boundscheck(False) # turn off bounds-checking
def myfunc1(np.ndarray[DTYPE_FLOAT_t] a):
do things here
def myfunc2(np.ndarray[DTYPE_FLOAT_t] b):
do things here
Or do I need to do this:
import numpy as np
cimport numpy as np
cimport cython
ctypedef np.float64_t DTYPE_FLOAT_t
@cython.wraparound (False) #turn off negative indexing
@cython.boundscheck(False) # turn off bounds-checking
def myfunc1(np.ndarray[DTYPE_FLOAT_t] a):
do things here
@cython.wraparound (False) #turn off negative indexing
@cython.boundscheck(False) # turn off bounds-checking
def myfunc2(np.ndarray[DTYPE_FLOAT_t] b):
do things here
Thanks!
Answer: The
[documentation](http://cython.readthedocs.io/en/latest/src/reference/compilation.html#globally)
states that if you want to set a compiler directive globally, you need to do
so with a comment at the top of the file. eg.
#!python
#cython: language_level=3, boundscheck=False
|
Python Flask Login login_required redirecting
Question: I am working on a Flask app and using Flask-Login for authentication.
Everything is set up and running. However when the user logins in and attempts
to visit a page that requires login, they are redirected to the login page.
When watching the console, I get a 200 for the GET login page, a 200 for the
POST on the login, a 302 from the login page to the home page, and then
another 302 from the homepage back to login.
See code below.
from flask import (Flask, render_template, g, flash, redirect, url_for,
request)
from flask_bcrypt import check_password_hash
from flask_login import (LoginManager, UserMixin, login_required, login_user,
logout_user, current_user)
import models
import forms
application = Flask(__name__)
application.secret_key = "xxx-xxx-xxx-xxx"
login_manager = LoginManager()
login_manager.init_app(application)
login_manager.login_view = "login"
@application.before_request
def before_request():
g.db = models.DATABASE
g.db.connect()
g.user = current_user
@application.after_request
def after_request(response):
g.db.close()
return response
@login_manager.user_loader
def load_user(email):
try:
return models.User.select().where(
models.User.email == email).get()
except models.DoesNotExist:
return None
@application.route("/register", methods=['GET', 'POST'])
def register():
form = forms.RegisterForm()
if form.validate_on_submit():
flash("Yay! You registered!", "success")
models.User.create_user(
email = form.email.data,
password = form.password.data
)
return redirect(url_for('home'))
return render_template('register.html',form=form)
@application.route("/login", methods=['GET', 'POST'])
def login():
form = forms.LoginForm()
if form.validate_on_submit():
next = request.args.get('next')
try:
user = models.User.get(models.User.email == form.email.data)
except models.DoesNotExist:
flash("Your email or password doesn't match!", "error")
else:
if check_password_hash(user.password, form.password.data):
login_user(user, remember=True)
flash("Welcome back!", "success")
return redirect(next or url_for("home"))
else:
flash("Your email or password doesn't match!", "error")
return render_template("login.html", form=form)
@application.route("/logout")
@login_required
def logout():
logout_user()
flash("You've been logged out!", "success")
return redirect(url_for("home"))
@application.route("/")
@login_required
def home():
return render_template("home.html")
if __name__ == "__main__":
models.initialize()
application.run(host='0.0.0.0')
Here is the model:
import datetime
from flask_login import UserMixin
from flask_bcrypt import generate_password_hash, check_password_hash
from peewee import *
DATABASE = MySQLDatabase("fakedatabasename", host="fakehostname", user="fakeusername", password="fakepassword")
class BaseModel(Model):
class Meta:
database = DATABASE
class Preachers(BaseModel):
preacher_id = PrimaryKeyField()
preacher_first_name = CharField(max_length=27)
preacher_last_name = CharField(max_length=27)
preacher_email = CharField()
class Sermons(BaseModel):
sermon_id = PrimaryKeyField()
sermon_title = CharField(max_length=27)
sermon_description = CharField(max_length=140)
sermon_date = DateTimeField(default=datetime.datetime.now())
sermon_preacher_id = IntegerField()
sermon_video_uri = CharField(max_length=255)
class User(UserMixin,BaseModel):
user_id = PrimaryKeyField()
email = CharField(index=True, unique=True)
password = CharField()
date_created = DateTimeField(default=datetime.datetime.now())
@classmethod
def create_user(cls, email, password):
try:
cls.create(
email = email,
password = generate_password_hash(password)
)
except IntegrityError:
raise ValueError("User already exists")
def initialize():
DATABASE.connect()
DATABASE.create_tables([Preachers, Sermons, User], safe=True)
DATABASE.close()
Answer: So it turns out that when working with Peewee and Flask-Login, you need to let
Peewee supply its default primary key for the User model instead of using a
custom one. Removing `user_id = PrimaryKeyField()`, dropping the table, and
restarting fixed it.
|
regex - swap two phrases around
Question: Python 3. Each line is constructed of a piece of text, then a pipe symbol,
then a second piece of text. I want to swap the two pieces of text around and
remove the pipe. This is the code so far:
p = re.compile('^(.*) \| (.*)$', re.IGNORECASE)
mytext = p.sub(r'\2\1', mytext)
Yet for some reason that I can't work out, it is not matching. A sample of the
text it should be matching is (ironically):
(https://www.youtube.com/watch?v=NIKdKCQnbNo) | [Regular Expressions 101 - YouTube]
and should end up like:
[The Field Expedient Pump Drill - YouTube](https://www.youtube.com/watch?v=4QDXUxTrlRw)
(in other words, the code is formatting the links into the format expected of
a markdown converter).
Here is the full code:
#! /usr/bin/env python3
import re, os
def create_text(myinputfile):
with open(myinputfile, 'r', encoding='utf-8') as infile:
mytext = infile.read()
return mytext
def reg_replace(mytext):
p = re.compile('^(.*) \| (.*)$', re.IGNORECASE)
mytext = p.sub(r'\2\1', mytext)
return mytext
def write_out(mytext, myfinalfile):
with open(myfinalfile, 'w') as myoutfile:
myoutfile.write(mytext)
def main():
mytext = create_text('out.md')
mytext = reg_replace(mytext)
write_out(mytext, 'out1.md')
os.rename("out.md", "out_original.md")
os.rename("out1.md", "out.md")
main()
Answer: This should help you. (View demo on
[regex101](https://regex101.com/r/hW2kR9/2))
(\S+)\s*\|\s*(.+)
Sub with:
\2\1
|
Python3 always shows ImportError message
Question: Whenever I try to run a script the python interpreter always shows an
`ImportError` message such as (e.g.) `No module named 'setuptools'`. So, I
tried install (or to satisfy this requirement) with `apt-get`... I do this for
both Python 2.7 and Python 3.5 until `Requirement already satisfied`.
First of all, I don't work with Python 2.7, but it's the defaul version for
the interpreter. So, how could I solve this problem to work with Python 3.5? I
tried this:
>>> import sys
>>> print(sys.path)
['',
'/usr/local/lib/python35.zip',
'/usr/local/lib/python3.5',
'/usr/local/lib/python3.5/plat-linux',
'/usr/local/lib/python3.5/lib-dynload',
'/usr/local/lib/python3.5/site-packages']
This was for **Python3** , for Python2 I did the same to compare the paths and
I got this:
>>> import sys
>>> print(sys.path)
['',
'/usr/local/lib/python2.7/dist-packages/pygame-1.9.2b8-py2.7-linux-x86_64.egg',
'/usr/lib/python2.7',
'/usr/lib/python2.7/plat-x86_64-linux-gnu',
'/usr/lib/python2.7/lib-tk',
'/usr/lib/python2.7/lib-old',
'/usr/lib/python2.7/lib-dynload',
'/usr/local/lib/python2.7/dist-packages',
'/usr/lib/python2.7/dist-packages',
'/usr/lib/python2.7/dist-packages/PILcompat',
'/usr/lib/python2.7/dist-packages/gtk-2.0']
Now... Should it work if I use the `append()` method to add all the paths of
Python2 to the paths in Python3? Also, I've been considered to completely
uninstall Python2, but I know this will cause more problems in my system that
the one I try to solve.
Answer: try :
python3.5 -m pip install setuptools
|
import hooks (custom module loaders) for pypy do not work
Question: I'm successfully able to create import hooks to load files directly from
memory in python2.7. The example I used was the accepted response to this
question:
[python:Import module from
memory](http://stackoverflow.com/questions/14191900/pythonimport-module-from-
memory)
However; when applying this code on pypy; i get an import error. I have also
tried other import hook examples that work with regular python but not with
pypy, such as this:
[python load zip with modules from
memory](http://stackoverflow.com/questions/39135750/python-load-zip-with-
modules-from-memory/39136473#39136473)
Does anyone know why import hooks do not work in pypy? Is there something I am
missing?
Answer: The problem is that in both of the examples you point to, `load_module()` does
not add the loaded module to `sys.modules`. Normally, it should do so (and
then PyPy works like CPython).
If `load_module()` does not add the module to `sys.modules`, then every single
`import a` will call `load_module()` again and return a new copy of the
module. For example, in the example from [python:Import module from
memory](http://stackoverflow.com/questions/14191900/pythonimport-module-from-
memory):
import a as a1
import a as a2
print a1 is a2 # False!
a1.foo = "foo"
print a2.foo # AttributeError
This is documented in <https://www.python.org/dev/peps/pep-0302/#id27>. The
`load_module()` method is responsible for doing more checks than these simple
examples show. In particular, note this line (emphasis in the original):
> Note that the module object _must_ be in sys.modules before the loader
> executes the module code.
So, the fact that PyPy behaves differently than CPython in this case could be
understood as a behavior difference that follows from code that fails to
respect the docs.
But anyway, my opinion is that it should be fixed. I've created an issue at
<https://bitbucket.org/pypy/pypy/issues/2382/sysmeta_path-not-working-like-
cpythons>.
|
python multi inheritance with parent classes have different __init__()
Question: Here both `B` and `C` are derived from `A`, but with different `__init__()`
parameters. My question is how to write the correct/elegant code here to
initialize self.a,self.b,self.c1,self.c2 in the following example? Maybe
another question is--is it a good coding practice to do this variable setting
in `__init()__` function or it is better to use simpler `__init__()` function,
and do `set()` function for each class later, which seems not as simple as to
just do it in `__init()__`?
class A(object):
__init__(self,a):
self.a=a
class B(A):
__init__(self,a,b):
super(B,self).__init__(a)
self.b=b
class C(A):
__init__(self,a,c1,c2):
super(C,self).__init__(a)
self.c1=c1
self.c2=c2
class D(B,C)
__init__(self,a,b,c1,c2,d):
#how to write the correct/elegant code here to initialize self.a,self.b,self.c1,self.c2?
#can I use super(D,self) something?
self.d=d
self.dd=self.a+self.b+2*self.c1+5*self.c2+3*self.d
d=D(1,2,3,4,5)
Answer: Multiple inheritance in Python requires that all the classes cooperate to make
it work. In this case, you can make them cooperate by having the `__init__`
method in each class accept arbitrary `**kwargs` and pass them on when they
call `super().__init__`.
For your example class hierarchy, you could do something like this:
class A(object):
__init__(self,a): # Don't accept **kwargs here! Any extra arguments are an error!
self.a=a
class B(A):
__init__(self, b, **kwargs): # only name the arg we care about (the rest go in **kwargs)
super(B, self).__init__(**kwargs) # pass on the other keyword args
self.b=b
class C(A):
__init__(self, c1, c2, **kwargs):
super(C,self).__init__(**kwargs)
self.c1=c1
self.c2=c2
class D(B,C)
__init__(self, d, **kwargs):
super(D,self).__init__(**kwargs)
self.d=d
self.dd=self.a+self.b+2*self.c1+5*self.c2+3*self.d
Note that if you wanted `D` to use the argument values directly (rather than
using `self.a`, etc.), you could both take them as named arguments and still
pass them on in the `super()` call:
class D(B,C)
__init__(self,a, b, c1, c2, d, **kwargs): # **kwargs in case there's further inheritance
super(D,self).__init__(a=a, b=b, c1=c1, c2=c2, **kwargs)
self.d = d
self.dd = a + b + 2 * c1 + 5 * c2 + 3 * d # no `self` needed in this expression!
Accepting and passing on some args is important if some of the parent classes
don't save the arguments (in their original form) as attributes, but you need
those values. You can also use this style of code to pass on modified values
for some of the arguments (e.g. with `super(D, self).__init__(a=a, b=b,
c1=2*c1, c2=5*c2, **kwargs)`).
This kind of collaborative multiple inheritance with varying arguments is
almost impossible to make work using positional arguments. With keyword
arguments though, the order of the names and values in a call doesn't matter,
so it's easy to pass on named arguments and `**kwargs` at the same time
without anything breaking. Using `*args` doesn't work as well (though recent
versions of Python 3 are more flexible about how you can call functions with
`*args`, such as allowing multiple unpackings in a single call: `f(*foo, bar,
*baz)`).
If you were using Python 3 (I'm assuming not, since you're explicitly passing
arguments to `super`), you could make the arguments to your collaborative
functions "keyword-only", which would prevent users from getting very mixed up
and trying to call your methods with positional arguments. Just put a bare `*`
in the argument list before the other named arguments: `def __init__(self, *,
c1, c2, **kwargs):`.
|
How do I configure Read the Docs to use sphinx-autodoc-annotation?
Question: I'm using sphinx-autodoc-annotation to read the function annotations in my
Python code and use that to generate the appropriate expected argument types
and return types. It's working great on my local machine, but I had to `pip
install sphinx-autodoc-annotation` of course.
I'm trying to generate the same documentation using [Read the
Docs](https://readthedocs.org/), but it gives me an error:
Could not import extension sphinx_autodoc_annotation (exception: No module named sphinx_autodoc_annotation)
Is it possible to configure Read the Docs to work with sphinx-autodoc-
annotation, and if so, how do I make it work?
Answer: Activate the _Install Project_ option for your Read the Docs project.
If the option is activated, Read the Docs will try to execute `setup.py
install` on your package (see: [RtD docs](https://read-the-
docs.readthedocs.io/en/latest/builds.html#understanding-what-s-going-on)). In
`setup.py`, you can install packages as specified in your [requirements
file](https://pip.readthedocs.io/en/1.1/requirements.html). Have a look at the
[source code of the Flask-MongoRest project](https://github.com/closeio/flask-
mongorest) for an example.
Add `sphinx-autodoc-annotation` as the only requirement to your
`requirements.txt` file.
|
Python code won't run?
Question: Hello i was wondering why this code will not run,thanks.
count = 0
finished = False
total = 0
while not finished:
number = int(input("Enter a number(0 to finish)"))
if number == 0:
finished = True
else:
total = total + number
count = count + 1
print("the average is", total/ count)
count = 0
Answer: It does run, the only issue I can see is that your else is indented inside
your if block. In Python, indentation is important in a way that curled
brackets or keywords are important in other programming languages.
count = 0
finished = False
total = 0
while not finished:
number = int(input("Enter a number(0 to finish)"))
if number == 0:
finished = True
else:
total = total + number
count = count + 1
print("the average is", total/ count)
count = 0
|
Under what condition does a Python subprocess get a SIGPIPE?
Question: I am reading the the Python documentation on the Popen class in the subprocess
module section and I came across the following code:
p1 = Popen(["dmesg"], stdout=PIPE)
p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
p1.stdout.close() # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]
The
[documentation](https://docs.python.org/2/library/subprocess.html#replacing-
shell-pipeline) also states that
> "The p1.stdout.close() call after starting the p2 is important in order for
> p1 to receive a SIGPIPE if p2 exits before p1.
Why must the p1.stdout be closed before we can receive a SIGPIPE and how does
p1 knows that p2 exits before p1 if we already closed it?
Answer: `SIGPIPE` is a signal that would be sent if `dmesg` tried to write to a closed
pipe. Here, `dmesg` ends up with _two_ targets to write to, your Python
process and the `grep` process.
That's because `subprocess` clones file handles (using the [`os.dup2()`
function](https://docs.python.org/2/library/os.html#os.dup2)). Configuring
`p2` to use `p1.stdout` triggers a `os.dup2()` call that asks the OS to
duplicate the pipe filehandle; the duplicate is used to connect `dmesg` to
`grep`.
With two open file handles for `dmesg` stdout, `dmesg` is never given a
`SIGPIPE` signal if only _one_ of them closes early, so `grep` closing would
never be detected. `dmesg` would needlessly continue to produce output.
So by closing `p1.stdout` immediately, you ensure that the only remaining
filehandle reading from `dmesg` stdout is the `grep` process, and if that
process were to exit, `dmesg` receives a `SIGPIPE`.
|
Python Pandas subsetting based on Dates
Question: I got a dataframe (using pandas) which contains the following fields:
1. Datesf-----------Price
2. 02/08/16 17:28--10
3. 02/08/16 17:29--20
4. 02/08/16 17:30--30
5. 03/08/16 09:00--40
6. 04/08/16 09:00--50
I am trying to subset the data frame into new dataframes using "Datesf" as a
filter. The subsetting should only use the Datesf.Date() part of variable
"Datesf" and name the new dataframe "df" as df_date. for example> new
subsetted Dataframe name> df_02_08_16
1\. Datesf------------Price
2\. 02/08/16 17:28--10 3\. 02/08/16 17:29--20 4\. 02/08/16 17:30--30
I tried using the following code but obviously, I am missing out quite a few
bits:
datelist= df["Datesf"].map(pd.Timestamp.date).unique()
for d in datelist:
print d
df.loc[df['Datesf'] == '%s' % d]
My python skills are relatively basic at this stage. so forgive me if my query
is not so challenging. Many thanks. regards, S
Answer: This should do the work.
import pandas as pd
df = pd.DataFrame([['02/08/16 17:28',1], ['02/08/16 17:28',10],['02/08/16 17:28',100],['03/08/16 17:28',101],['04/08/16 17:28',103]], columns=['Datesf', 'Price'])
df.Datesf = pd.to_datetime(df.Datesf)
unique_dates = df.Datesf.unique()
data_frame_dict = {elem : pd.DataFrame for elem in unique_dates}
for n, key in enumerate(data_frame_dict.keys()):
print ' ==== dataframe %d ======' % n
data_frame_dict[key] = df[:][df.Datesf == key]
print data_frame_dict[key]
data_frame_dict[key].to_csv('%s.csv'%str(key))
|
Run unit test code from zip file
Question: I followed this tutorial to create a self contained python application.
<http://blog.ablepear.com/2012/10/bundling-python-files-into-stand-alone.html>
What I would like to do is create a unit test application within a similar
self contained application and, in addition, have several fiels within the
unit test application itself.
I have a directory structure as follows: src/ src1.py src2.py **main**.py
test/ **main**.py **init**.py
My unittest application packages up the src and test files to create a self-
contained unit test application. I currently have all my test code in
test/**main**.py and would like to separate the test code into different files
(i.e. test1.py, test2.py, etc). However, when I try to do so, it either can't
import them or I get import errors.
What is the correct way to implement this scheme? I am using the unittest
module in Python 2.7 and would like to continue using these.
Answer: Actually, I got this working by following this:
<http://blakesmith.me/2009/09/14/getting-started-with-python-unit-
testing.html> Instead of calling it suite.py, I called it **main**.py and it
worked within a zip file.
|
Splitting strings in python using import re
Question: Why does this work:
string = 'N{P}[ST]{P}'
>>> import re
>>> re.split(r"[\[\]]", string)
>>> ['N{P}', 'ST', '{P}']
But this don't?
>>> re.split(r"{\{\}}", string)
Answer: You have to do this:
re.split(r"[{}]", string)
`r"{\{\}}"` is a special re syntax to repeat groups (ex: `(ab){1,3}` matches
`ab`, `abab` or `ababab`) but not the character range (note that you don't
have to escape the curly braces in a character range). (I admit I don't know
what your strange regex is supposed to do specially in the re.split context,
but not what you want :))
|
Python/Requests: Correct login returns 401 unauthorized
Question: I have a python application logs in to a remote host via basic HTTP
authentication. Authentication is as follows:
def make_authenticated_request(host, username, password):
url = host
r = requests.get(url, auth=(username, password))
r.raise_for_status()
return r
test = Looter.make_authenticated_request("http://" + host + "/status/status_deviceinfo.htm", user, password)
This error is printed:
`401 Client Error: Unauthorized for url`
Strange thing is that this doesn't always happen. It randomly fails/succeeds,
for the same host with the same credentials.
Login is however correct, and works flawlessly in my browser. I'm no python
ninja. Any clues ?
Answer: I might rewrite it to look something like this.. change it around however you
need or like. The point here is that i'm using a session and passing it around
to make another requests. You can reuse that session object to make other
requests. Now if you making lots of requests an authing in each time like your
code suggests. The site could be locking you out, which is why a session works
better because you don't have to continue to auth in.
import requests
class Looter(object):
def __init__(self):
self.s = None
def create_session(self, url, username, password):
# create a Session
s = requests.Session()
# auth in
res = s.get(url, auth=(username, password))
if res.status_code == 200:
self.s = s
def make_request(self, url):
self.s.get(url)
#do something with the requests
l = Looter()
l.create_session(url, username, password)
# print the session to see if it authed in
print l.s.status_code
|
Python automate key press of a QtGUI
Question: I have a python script with the section below:
for index in range(1,10):
os.system('./test')
os.system('xdotool key Return')
What I want to do is to run the executable ./test, which brings up a QtGUI. In
this GUI, a key press prompt buton comes up. I want to automate this key press
of the GUI so that the executable continues.
My python script though runs the executable, the GUI prompt comes up and a key
press is not entered until after the executable. Is there any way to fix this?
Answer: `os.system` doesn't return until the child process exits. You need
`subprocess.Popen`. It's also a good idea to `sleep` a while before sending
keystrokes (it may take some time for the child process to get ready to accept
user input):
from subprocess import Popen
from time import sleep
for index in range(1,10):
# start the child
process = Popen('./test')
# sleep to allow the child to draw its buttons
sleep(.333)
# send the keystroke
os.system('xdotool key Return')
# wait till the child exits
process.wait()
I'm not shure that you need the last line. If all **9** child processes are
supposed to stay alive -- remove it.
|
Python Mathematical signs in function parameter?
Question: I would like to know if there is a way to add math symbols into the function
parameters.
def math(x, y, symbol):
answer = x 'symbol' y
return answer
this is an small example what I mean.
**EDIT: here is the whole problem**
def code_message(str_val, str_val2, symbol1, symbol2):
for char in str_val:
while char.isalpha() == True:
code = int(ord(char))
if code < ord('Z'):
code symbol1= key
str_val2 += str(chr(code))
elif code > ord('z'):
code symbol1= key
str_val2 += str(chr(code))
elif code > ord('A'):
code symbol2= key
str_val2 += str(chr(code))
elif code < ord('a'):
code symbol2= key
str_val2 += str(chr(code))
break
if char.isalpha() == False:
str_val2 += char
return str_val2
I need to call the function a number of times but sometimes with a +/- for
first symbol and sometimes a +/- for second symbol
ORIGINAL CODE :
def code_message(str_val, str_val2):
for char in str_val:
while char.isalpha() == True:
code = int(ord(char))
if code < ord('Z'):
code -= key
str_val2 += str(chr(code))
elif code > ord('z'):
code -= key
str_val2 += str(chr(code))
elif code > ord('A'):
code += key
str_val2 += str(chr(code))
elif code < ord('a'):
code += key
str_val2 += str(chr(code))
break
if char.isalpha() == False:
str_val2 += char
return str_val2
Answer: You can not pass operator to the function, but however you may pass operator's
functions defined in
[`operator`](https://docs.python.org/2/library/operator.html) library. Hence,
your function will be like:
>>> from operator import eq, add, sub
>>> def magic(left, op, right):
... return op(left, right)
...
**Examples** :
# To Add
>>> magic(3, add, 5)
8
# To Subtract
>>> magic(3, sub, 5)
-2
# To check equality
>>> magic(3, eq, 3)
True
**Note** : I am using function as `magic` instead of `math` because `math` is
default python library and it is not good practice to use predefined keywords.
|
How to refresh multiple printed lines inplace using Python?
Question: I would like to understand how to reprint multiple lines in Python 3.5.
This is an example of a script where I would like to refresh the printed
statement in place.
import random
import time
a = 0
while True:
statement = """
Line {}
Line {}
Line {}
Value = {}
""".format(random.random(), random.random(), random.random(), a)
print(statement, end='\r')
time.sleep(1)
a += 1
What I am trying to do is have:
Line 1
Line 2
Line 3
Value = 1
Write on top of / update / refresh:
Line 1
Line 2
Line 3
Value = 0
The values of each line will change each time. This is effectively giving me a
status update of each Line.
I saw [another question from 5 years
ago](https://stackoverflow.com/questions/6840420/python-rewrite-multiple-
lines-in-the-console?noredirect=1&lq=1) however with the addition of the `end`
argument in Python 3+ print function, I am hoping that there is a much simpler
solution.
Answer: If I've understood correctly you're looking for this type of solution:
import random
import time
import os
def clear_screen():
os.system('cls' if os.name == 'nt' else 'clear')
a = 0
while True:
clear_screen()
statement = """
Line {}
Line {}
Line {}
Value = {}
""".format(random.random(), random.random(), random.random(), a)
print(statement, end='\r')
time.sleep(1)
a += 1
This solution won't work with some software like IDLE, Sublime Text,
Eclipse... The problem with running it within this type of software is that
clear/cls uses ANSI escape sequences to clear the screen. These commands write
a string such as "\033[[80;j" to the output buffer. The native command prompt
is able to interpret this as a command to clear the screen but these pseudo-
terminals don't know how to interpret it, so they just end up printing small
square as if printing an unknown character.
If you're using this type of software, one hack around could be doing
print('\n' * 100), it won't be the optimal solution but it's better than
nothing.
|
Import Winreg in a Python Script
Question: I am currently working on a Jenkins freestyle job and one of the build steps
is to run a Python script. I have been working on this job for a couple of
days now and this is one of the last build steps needed to finish it off. I
have reached a point where I get an error letting me know that the **import
winreg** module does not exist.
I have installed Jenkins on CentOS and have read some documentation stating
that I am unable to import this module on this distribution.
Is there no other way to solve this than to switch over to a Windows machine?
Thanks
Answer: It makes sense, the [_winreg
docs](https://docs.python.org/2/library/_winreg.html#module-_winreg) says:
> These functions expose the Windows registry API to Python.
You could try to make it run on a windows virtual machine in your centos host
or just following the official
[Installing+Jenkins+on+Red+Hat+distributions](https://wiki.jenkins-
ci.org/display/JENKINS/Installing+Jenkins+on+Red+Hat+distributions) guide
|
setup.py console_scripts entry point does not resolve import
Question: I have following setup.py:
from setuptools import setup
from distutils.core import setup
setup(
name="foobar",
version="0.1.0",
author="Batman",
author_email="[email protected]",
packages = ["foobar"],
include_package_data=True,
install_requires=[
"asyncio",
],
entry_points={
'console_scripts': [
'foobar = foobar.__main__:main'
]
},
)
Now, the **main**.py file gets installed and callable by foobar out of console
after installation, which is what I wanted. Problem is, **main**.py has import
at line 3 and that does not work.
So my folder structure is as follows
dummy/setup.py
dummy/requirements.txt
dummy/foobar/__init__.py
dummy/foobar/__main__.py
dummy/foobar/wont_be_imported_one.py
I run `python3 setup.py bdist` being in dummy directory. Upon running foobar
after installation, I get error
File "/usr/local/bin/foobar", line 9, in <module>
load_entry_point('foobar==0.1.0', 'console_scripts', 'foobar')()
[...]
ImportError: No module named 'wont_be_imported_one'.
UPDATE. `__init__.py` has content of
from wont_be_imported_one import wont_be_imported_one
`wont_be_imported_one.py` has from `wont_be_imported_one` function which I
actually need to import.
Answer: In Python 3, `import`s are absolute by default, and so `from
wont_be_imported_one import ...` inside of `foobar` will be interpreted as a
reference to some module named `wont_be_imported_one` outside of `foobar`. You
need to use a relative import instead:
from .wont_be_imported_one import wont_be_imported_one
# ^ Add this
See [PEP 328](https://www.python.org/dev/peps/pep-0328/) for more information.
|
Basic Bar Chart with plotly
Question: I try to do a bar charts, with this code
import plotly.plotly as py
import plotly.graph_objs as go
data = [go.Bar(
x=['giraffes', 'orangutans', 'monkeys'],
y=[20, 14, 23]
)]
py.iplot(data, filename='basic-bar')
But I got this error :
>
> PlotlyLocalCredentialsError Traceback (most recent call
> last)
> <ipython-input-42-9eae40f28f37> in <module>()
> 3 y=[20, 14, 23]
> 4 )]
> ----> 5 py.iplot(data, filename='basic-bar')
>
> C:\Users\Demonstrator\Anaconda3\lib\site-
> packages\plotly\plotly\plotly.py
>
>
> in iplot(figure_or_data, **plot_options) 149 if 'auto_open' not in
> plot_options: 150 plot_options['auto_open'] = False \--> 151 url =
> plot(figure_or_data, **plot_options) 152 153 if isinstance(figure_or_data,
> dict):
>
>
> C:\Users\Demonstrator\Anaconda3\lib\site-
> packages\plotly\plotly\plotly.py
>
>
> in plot(figure_or_data, validate, **plot_options) 239 240 plot_options =
> _plot_option_logic(plot_options) \--> 241 res = _send_to_plotly(figure,
> **plot_options) 242 if res['error'] == '': 243 if plot_options['auto_open']:
>
>
> C:\Users\Demonstrator\Anaconda3\lib\site-
> packages\plotly\plotly\plotly.py
>
>
> in _send_to_plotly(figure, **plot_options) 1401 cls=utils.PlotlyJSONEncoder)
> 1402 credentials = get_credentials() -> 1403
> validate_credentials(credentials) 1404 username = credentials['username']
> 1405 api_key = credentials['api_key']
>
>
> C:\Users\Demonstrator\Anaconda3\lib\site-
> packages\plotly\plotly\plotly.py
>
>
> in validate_credentials(credentials) 1350 api_key =
> credentials.get('api_key') 1351 if not username or not api_key: -> 1352
> raise exceptions.PlotlyLocalCredentialsError() 1353 1354
>
>
> PlotlyLocalCredentialsError:
> Couldn't find a 'username', 'api-key' pair for you on your local
> machine. To sign in temporarily (until you stop running Python), run:
> >>> import plotly.plotly as py
> >>> py.sign_in('username', 'api_key')
>
> Even better, save your credentials permanently using the 'tools' module:
> >>> import plotly.tools as tls
> >>> tls.set_credentials_file(username='username', api_key='api-key')
>
> For more help, see https://plot.ly/python.
>
Any idea to help me please?
Thank you
Answer: You need to pay attention to the traceback in the error. In this case, it's
even more helpful than usual. The solution is given to you here:
PlotlyLocalCredentialsError:
Couldn't find a 'username', 'api-key' pair for you on your local machine. To sign in temporarily (until you stop running Python), run:
>>> import plotly.plotly as py
>>> py.sign_in('username', 'api_key')
Even better, save your credentials permanently using the 'tools' module:
>>> import plotly.tools as tls
>>> tls.set_credentials_file(username='username', api_key='api-key')
For more help, see https://plot.ly/python.
So, enter your credentials used when you signed up to the site before you
attempt to make a plot. You may have to sign in in a web browser and request
for an API key to be generated, it is not the same as your password.
|
python google app engine stripe integration
Question: I am working on a project in which i want to integrate stripe for payments. I
am following their documentation to integrate it in python [Stripe
Documentation](https://stripe.com/docs/charges). In documentation they
downloaded the stripe library to use it. The code to download it was:
pip install --upgrade stripe
I followed the same steps. But i am getting this error. When i try to import
it in my project.
import stripe
ImportError: No module named stripe
Answer: The proper way to install a 3rd party library into your GAE application is
described in [Installing a
library](https://cloud.google.com/appengine/docs/python/tools/using-libraries-
python-27?hl=en#installing_a_library):
> The easiest way to manage this is with a ./lib directory:
>
> 1. Use pip to install the library and the vendor module to enable
> importing packages from the third-party library directory.
>
> 2. Create a directory named lib in your application root directory:
>
> > mkdir lib
>
>
> 3. To tell your app how to find libraries in this directory, create or
> modify a file named appengine_config.py in the root of your project, then
> add these lines:
>
> > from google.appengine.ext import vendor
>
> # Add any libraries installed in the "lib" folder.
> vendor.add('lib')
>
>
> 4. Use pip with the -t lib flag to install libraries in this directory:
>
> > pip install -t lib gcloud
>
>
>
**Notes** :
* When going through the mentioned doc page pay attention as it also contains instructions for requesting and using GAE-provided _built-in_ libraries - different than those for _installed/vendored-in_ libraries.
* if your app is a multi-module one you'll need an `appengine_config.py` for each module using the library at step#3, located beside the module's `.yaml` file. It can be symlinked for DRY reasons if you prefer (see <http://stackoverflow.com/a/34291789/4495081>).
* step #4's goal is to just bring the content of the stripe library in a subdirectory of the `lib` dir. You can do that manually if the pip way fails for whatever reason.
|
Change the width of the Basic Bar Chart
Question: I create a Bar Chart with matplotlib with :
import matplotlib.pyplot as plt; plt.rcdefaults()
import numpy as np
import matplotlib.pyplot as plt
objects = ('ETA_PRG_P2REF_RM', 'ETA_PRG_VDES_RM', 'ETA_PRG_P3REF_RM', 'Python', 'C++', 'Java', 'Perl', 'Scala', 'Lisp')
y_pos = np.arange(len(objects))
performance = [220010, 234690, 235100, 21220, 83410, 119770, 210990, 190430, 888994]
plt.bar(y_pos, performance, align='center', alpha=0.5)
plt.xticks(y_pos, objects)
plt.ylabel('Usage')
plt.title('Programming language usage')
plt.show()
Look at the attached Image [](http://i.stack.imgur.com/MAUfd.png)
But, As you can remark the width of the plot is smal, the name of object are
not clear. Can you suggest me how to resolve this problem?
Thank you
Answer: You can add tick labels with a rotation:
pyplot.xticks(y_pos, objects, rotation=70)
In addition to an angle in degrees, you can specify a string:
pyplot.xticks(y_pos, objects, rotation='vertical')
You may also want to specify a horizontal alignment, especially is using an
angle like 40. The default is to use the center, which makes the labels look
weird:
pyplot.xticks(y_pos, objects, rotation=40, ha='right')
See the
[docs](http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.xticks) for
a full list of options.
|
Python classes: method has same name as property
Question: I'm constructing a class Heating. Every instance of this class has the
property 'temperature'. It's mandatory that Heating also supports the method
temperature() that prints the property 'temperature' as an integer.
When I call the method temperature() I get the error 'int' object is not
callable because self.temperature is already defined as an integer.
How do I solve this?
code:
class Heating:
"""
>>> machine1 = Heating('radiator kitchen', temperature=20)
>>> machine2 = Heating('radiator living', minimum=15, temperature=18)
>>> machine3 = Heating('radiator bathroom', temperature=22, minimum=18, maximum=28)
>>> print(machine1)
radiator kitchen: current temperature: 20.0; allowed min: 0.0; allowed max: 100.0
>>> machine2
Heating('radiator living', 18.0, 15.0, 100.0)
>>> machine2.changeTemperature(8)
>>> machine2.temperature()
26.0
>>> machine3.changeTemperature(-5)
>>> machine3
Heating('radiator bathroom', 18.0, 18.0, 28.0)
"""
def __init__(self, name, temperature = 10, minimum = 0, maximum = 100):
self.name = name
self.temperature = temperature
self.minimum = minimum
self.maximum = maximum
def __str__(self):
return '{0}: current temperature: {1:.1f}; allowed min: {2:.1f}; allowed max: {3:.1f}'.format(self.name, self.temperature, self.minimum, self.maximum)
def __repr__(self):
return 'Heating(\'{0}\', {1:.1f}, {2:.1f}, {3:.1f})'.format(self.name, self.temperature, self.minimum, self.maximum)
def changeTemperature(self, increment):
self.temperature += increment
if self.temperature < self.minimum:
self.temperature = self.minimum
if self.temperature > self.maximum:
self.temperature = self.maximum
def temperature(self):
return self.temperature
# testen van het programma
if __name__ == '__main__':
import doctest
doctest.testmod()
Answer: You can't have both a method and an attribute with the same name. Methods are
attributes too, albeit ones that you can call.
Just rename the attribute to something else. You could use `_temperature`:
def __init__(self, name, temperature = 10, minimum = 0, maximum = 100):
self.name = name
self._temperature = temperature
self.minimum = minimum
self.maximum = maximum
def __str__(self):
return '{0}: current temperature: {1:.1f}; allowed min: {2:.1f}; allowed max: {3:.1f}'.format(self.name, self._temperature, self.minimum, self.maximum)
def __repr__(self):
return 'Heating(\'{0}\', {1:.1f}, {2:.1f}, {3:.1f})'.format(self.name, self._temperature, self.minimum, self.maximum)
def changeTemperature(self, increment):
self._temperature += increment
if self.temperature < self.minimum:
self._temperature = self.minimum
if self.temperature > self.maximum:
self._temperature = self.maximum
def temperature(self):
return self._temperature
Now your class has both `_temperature` (the integer) and `temperature()` (the
method); the latter returns the former.
|
Function within while loop not running more than once
Question: I am writing a small game as a way to try and learn python. At the bottom of
my code, there is a while loop which asks for user input. If that user input
is yes, it is supposed to update a variable, encounter_prob. If encounter_prob
is above 20, it is supposed to call the function. I can get this behavior to
happen, but only once. It seems to not be going through the if statement
again.
import random
def def_monster_attack():
monster_attack = random.randrange(1,6)
return monster_attack
def def_player_attack():
player_attack = random.randrange(1,7)
return player_attack
def def_encounter_prob():
encounter_prob = random.randrange(1,100)
return encounter_prob
def def_action():
action = raw_input("Move forward? Yes or No")
return action
player = {
'hp': 100,
'mp': 100,
'xp': 0,
'str': 7
}
monster = {
'hp': 45,
'mp': 10,
'str': 6
}
def encounter():
while player['hp'] > 0 and monster['hp'] > 0:
keep_fighting = raw_input("Attack, Spell, Gaurd, or Run?")
if keep_fighting.startswith('a') == True:
player_attack = def_player_attack()
monster['hp'] = monster['hp'] - player_attack
monster_attack = def_monster_attack()
player['hp'] = player['hp'] - monster_attack
print "player's hp is", player['hp']
print "monster's hp is", monster['hp']
while player['hp'] > 0:
action = def_action()
if action.startswith('y') == True:
encounter_prob = def_encounter_prob()
if encounter_prob > 20:
encounter()
Answer: It's actually calling the function `encounter` twice but the first time ends
up killing the monster by decreasing its `hp` to 0 or below, while the second
time the function exits without entering the `while` loop because the
`monster['hp'] > 0` comparison evaluates to `False`. The monster's `hp` aren't
reset at each new encounter.
If you're having difficulties debugging your code, do not hesitate to put some
`print` statements in different places to examine the value of your data. This
should help you pinpointing what's going on.
|
How do I connect a PyQt5 slot to a signal function in a class?
Question: I'm trying to set up a pyqt signal between a block of UI code and a separate
python class that is just for handling event responses. I don't want to give
the UI code access to the handler (classic MVC style). Unfortunately, I am
having difficulty connecting the slot to the signal. Here is the code:
from PyQt5 import QtCore
from PyQt5.QtCore import QObject
class UiClass(QObject):
mySignal = QtCore.pyqtSignal( str )
def __init__(self):
QObject.__init__(self)
def send_signal(self):
self.mySignal.emit("Hello world!")
class HandlerClass():
currentMessage = "none"
def register(self, mySignal):
mySignal.connect(self.receive_signal)
@QtCore.pyqtSlot(str)
def receive_signal(self, message):
self.currentMessage = message
print(message)
ui = UiClass()
handler = HandlerClass()
handler.register(ui.mySignal)
ui.send_signal()
When I run this code it fails at the handler.register line. Here is the error:
> Traceback (most recent call last):
>
> File "C:\git\IonControl\testpyqtslot.py", line 25, in
>
> handler.register(ui.mySignal)
>
> File "C:\git\IonControl\testpyqtslot.py", line 17, in register
>
> mySignal.connect(self.receive_signal)
>
> TypeError: connect() failed between UiClass.mySignal[str] and
> receive_signal()
I'd like this code to successfully register the signal to the slot and have
the handler print "hello world" at the end. What did I do wrong here?
My basic question is this: how do I connect a signal to a slot function that
is part of a class?
Answer: The error happens becuase you are using `pyqtSlot` decorator in a class which
doesn't inherit from `QObject`. You can fix the problem by either getting rid
of the decorator, or making `HandlerClass` a subclass of `QObject`.
The main purpose of `pyqtSlot` is to allow several different overloads of a
slot to be defined, each with a different signature. It may also be needed
sometimes when making cross-thread connections. However, these use-cases are
relatively rare, and in most PyQt applications it is not necessary to use
`pyqtSlot` at all. Signals can be connected to **any** python callable object,
whether it is decorated as a slot or not.
|
Scrapy spider does not store state (persistent state)
Question: Hi have a basic spider that runs to fetch all links on a given domain. I want
to make sure it persists its state so that it can resume from where it left. I
have followed the given url <http://doc.scrapy.org/en/latest/topics/jobs.html>
.But when i try it the first time it runs fine and i end it with Ctrl+C and
when I try to resume it the crawl stops on the first url itself.
Below is the log when it ends:
2016-08-29 16:51:08 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 896,
'downloader/request_count': 4,
'downloader/request_method_count/GET': 4,
'downloader/response_bytes': 35320,
'downloader/response_count': 4,
'downloader/response_status_count/200': 4,
'dupefilter/filtered': 149,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2016, 8, 29, 16, 51, 8, 837853),
'log_count/DEBUG': 28,
'log_count/INFO': 7,
'offsite/domains': 22,
'offsite/filtered': 23,
'request_depth_max': 1,
'response_received_count': 4,
'scheduler/dequeued': 2,
'scheduler/dequeued/disk': 2,
'scheduler/enqueued': 2,
'scheduler/enqueued/disk': 2,
'start_time': datetime.datetime(2016, 8, 29, 16, 51, 7, 821974)}
2016-08-29 16:51:08 [scrapy] INFO: Spider closed (finished)
Here is my spider:
from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor
from Something.items import SomethingItem
class maxSpider(CrawlSpider):
name = 'something'
allowed_domains = ['thecheckeredflag.com', 'inautonews.com']
start_urls = ['http://www.thecheckeredflag.com/', 'http://www.inautonews.com/']
rules = (Rule(LinkExtractor(allow=()), callback='parse_obj', follow=True),)
def parse_obj(self,response):
for link in LinkExtractor(allow=self.allowed_domains,deny =() ).extract_links(response):
item = SomethingItem()
item['url'] = link.url
yield item
#print item
Scrapy version: Scrapy 1.1.2
Python version: 2.7
I am new to scrapy, if i need to post any more info please let me know.
Answer: The reason this was happening was due to the spider process being killed
abruptly.
The spider was not shutting down properly when I hit the Ctrl+C. Now, when the
crawler shuts down properly the first time, it resumes properly too.
So basically, make sure that you see the crawler ends/shuts down properly for
it to resume.
|
Querying postgresql for DateTime values between two dates
Question: I have the following dateTime text type variable in Postgres table
"2016-05-12T23:59:11+00:00"
"2016-05-13T11:00:11+00:00"
"2016-05-13T23:59:11+00:00"
"2016-05-15T10:10:11+00:00"
"2016-05-16T10:10:11+00:00"
"2016-05-17T10:10:11+00:00"
I have to write a Python function to extract the data for a few variables
between two dates
def fn(dateTime):
df1=pd.DataFrame()
query = """ SELECT "recordId" from "Table" where "dateTime" BETWEEN %s AND %s """ %(dStart,dEnd)
df1=pd.read_sql_query(query1,con=engine)
return df1
I need to create dStart and dEnd variables and use them as function parameters
as below
fn('2016-05-12','2016-05-15')
I tried using to_char("dateTime", 'YYYY-MM-DD') Postgres function but didn't
work out. Please let me know how to solve this
Answer: I'm not familiar with postgresql, but you can convert the strings to the
`struct_time` class which is part of the built in [`time`
package](https://docs.python.org/3/library/time.html) in Python and simply
make comparisons between them.
import time
time_data = ["2016-05-12T23:59:11+00:00",
"2016-05-13T11:00:11+00:00",
"2016-05-13T23:59:11+00:00",
"2016-05-15T10:10:11+00:00",
"2016-05-16T10:10:11+00:00",
"2016-05-17T10:10:11+00:00"]
def fn(t_init, t_fin, t_all):
# Convert string inputs to struct_time using time.strptime()
t_init, t_fin = [time.strptime(x, '%Y-%m-%d') for x in [t_init, t_fin]]
t_all = [time.strptime(x, '%Y-%m-%dT%H:%M:%S+00:00') for x in time_all]
out = []
for jj in range(len(t_all)):
if t_init < t_all[jj] < t_fin:
out.append(jj)
return out
out = fn('2016-05-12','2016-05-15', time_data)
print(out)
# [0, 1, 2]
The `time.strptime` routine uses a format specifiers to specify which parts of
the string correspond to different time components.
%Y Year with century as a decimal number.
%m Month as a decimal number [01,12].
%d Day of the month as a decimal number [01,31].
%H Hour (24-hour clock) as a decimal number [00,23].
%M Minute as a decimal number [00,59].
%S Second as a decimal number [00,61].
%z Time zone offset from UTC.
%a Locale's abbreviated weekday name.
%A Locale's full weekday name.
%b Locale's abbreviated month name.
%B Locale's full month name.
%c Locale's appropriate date and time representation.
%I Hour (12-hour clock) as a decimal number [01,12].
%p Locale's equivalent of either AM or PM.
|
SyntaxError: python Arabic encoding
Question: I have this Code -I am using Python 2.7- :
#!/usr/bin/python
# -*- Coding: UTF-8 -*-
import nltk
from nltk.tokenize import StanfordTokenizer
sentence = u"Ψ§ΩΨ³ΩΨ§Ω
ΨΉΩΩΩΩ
Ω Ψ±ΨΩ
Ψ© Ψ§ΩΩΩ Ω Ψ¨Ψ±ΩΨ§ΨͺΩ"
print StanfordTokenizer().tokenize(sentence)
I saved the code in a file called example.py, when I write python example.py
in the terminal I get the following error:
File "example.py", line 5
SyntaxError: Non-ASCII character '\xd8' in file example.py on line 5, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details
I already declared the type of encoding as UTF-8. So what is the problem?
However, if I run the code line by line in the terminal it is working and no
error.
Answer: > ... the first or second line must match the regular expression "^[
> \t\v]_#._?coding[:=][ \t]*([-_.a-zA-Z0-9]+)".
[source](https://www.python.org/dev/peps/pep-0263/)
Your encoding declaration does not match that regex. The `c` needs to be
lowercase.
|
zip unknown number of lists with Python for more than one list
Question: I need to do something very similar to what was asked here [How would you zip
an unknown number of lists in
Python?](http://stackoverflow.com/questions/5938786/how-would-you-zip-an-
unknown-number-of-lists-in-python), but in a more general case.
I have the following set up:
a = [['a', '0', 'b', 'f', '78']]
b = [['3', 'w', 'hh', '12', '8']]
c = [['g', '7', '1', 'a0', '9'], ['45', '4', 'fe', 'h', 'k']]
I need to zip these lists together to obtain:
abc = [['a', '3', 'g', '45'], ['0', 'w', '7', '4'], ['b', 'hh', '1', 'fe'], ['f', '12', 'a0', 'h'], ['78', '8', '9', 'k']]
which I can generate with:
zip(a[0], b[0], c[0], c[1])
But the lists `a,b,c` contain a number of sublists that will vary for
successive runs, so this "manual" way of expanding them won't work.
The closest I can get is:
zip(a[0], b[0], *c)
Since unpacking a list with `*` in any other position than the last is not
allowed, the "ideal" expression:
zip(*a, *b, *c)
does not work.
How could I zip together a number of lists with an unknown number of sublists?
Answer: `itertools.chain` to the rescue:
import itertools
z = list(zip(*itertools.chain(a, b, c)))
|
Subprocess.Popen vs Subprocess.call
Question: Using subprocess.Popen is producing incomplete results where as
subprocess.call is giving correct output
This is related to a regression script which has 6 jobs and each job performs
same task but on different input files. And I'm running everything in parallel
using SubProcess.Popen
Task is performed using a shell script which has calls to a bunch of
C-compiled executables whose job is to generate some text reports followed by
converting text report info into jpg images
sample of shell script (runit is the file name) with calling C-compile
executables
#!/bin/csh -f
#file name : runit
#C - Executable 1
clean_spgs
#C - Executable 2
scrub_spgs_all file1
scrub_spgs_all file2
#C - Executable 3
scrub_pick file1 1000
scrub_pick file2 1000
while using subprocess.Popen, both scrub_spgs_all and scrub_pick are trying to
run in parallel causing the script to generate incomplete results i.e. output
text files doesn't contain complete information and also missing some of
output text reports.
subprocess.Popen call is
resrun_proc = subprocess.Popen("./"+runrescompare, shell=True, cwd=rescompare_dir, stdout=subprocess.PIPE, stderr=subprocess.POPT, universal_newlines=True)
where runrescompare is a shell script and has
#!/bin/csh
#some other text
./runit
Where as using subprocess.call is generating all the output text files and jpg
images correctly but I can't run all 6 jobs in parallel.
resrun_proc = subprocess.call("./"+runrescompare, shell=True, cwd=rescompare_dir, stdout=subprocess.PIPE, stderr=subprocess.POPT, universal_newlines=True)
What is the correct way to call a C-exctuable from shell script using python
subprocess calls where all 6 jobs can run in parallel(using python 3.5.1?
Thanks.
Answer: You tried to simulate multiprocessing with subprocess.Popen() which does not
work like you want: the output is blocked after a while unless you consume it,
for instance with `communicate()` (but this is blocking) or by reading the
output, but with 6 concurrent handles in a loop, you are bound to get
deadlocks.
The best way is run the `subprocess.call` lines in separate threads.
There are several ways to do it. Small simple example with locking:
import threading,time
lock=threading.Lock()
def func1(a,b,c):
lock.acquire()
print(a,b,c)
lock.release()
time.sleep(10)
tl=[]
t = threading.Thread(target=func1,args=[1,2,3])
t.start()
tl.append(t)
t=threading.Thread(target=func1,args=[4,5,6])
t.start()
tl.append(t)
# wait for all threads to complete (if you want to wait, else
# you can skip this loop)
for t in tl:
t.join()
I took the time to create an example more suitable to your needs:
2 threads executing a command and getting the output, then printing it within
a lock to avoid mixup. I have used `check_output` method for this. I'm using
windows, and I list C and D drives in parallel.
import threading,time,subprocess
lock=threading.Lock()
def func1(runrescompare,rescompare_dir):
resrun_proc = subprocess.check_output(runrescompare, shell=True, cwd=rescompare_dir, stderr=subprocess.PIPE, universal_newlines=True)
lock.acquire()
print(resrun_proc)
lock.release()
tl=[]
t=threading.Thread(target=func1,args=["ls","C:/"])
t.start()
tl.append(t)
t=threading.Thread(target=func1,args=["ls","D:/"])
t.start()
tl.append(t)
# wait for all threads to complete (if you want to wait, else
# you can skip this loop)
for t in tl:
t.join()
|
Feature Importance for Random Forest Regressor in Python
Question: I'm trying to find out which features have the most importance for my
predictive model.
Currently I'm using sklearn's inbuilt attribute as such
Model = Model.fit(Train_Features, Labels_Train)
print(Model.feature_importances_)
It's just that its more of a black box type method, I'm not understanding what
method it uses to weight the importance towards the features. Is there a
better approach for doing this?
Answer: Feature importance is not a black-box when it comes to decision trees. From
the documentation for a [DecisionTreeRegressor](http://scikit-
learn.org/stable/modules/generated/sklearn.tree.DecisionTreeRegressor.html#sklearn.tree.DecisionTreeRegressor.feature_importances_):
> The importance of a feature is computed as the (normalized) total reduction
> of the criterion brought by that feature. It is also known as the Gini
> importance.
For a forest, it just averages across the different trees in your forest.
Check out the [source code](https://github.com/scikit-learn/scikit-
learn/blob/51a765a/sklearn/ensemble/forest.py#L322):
def feature_importances_(self):
"""Return the feature importances (the higher, the more important the
feature).
Returns
-------
feature_importances_ : array, shape = [n_features]
"""
if self.estimators_ is None or len(self.estimators_) == 0:
raise NotFittedError("Estimator not fitted, "
"call `fit` before `feature_importances_`.")
all_importances = Parallel(n_jobs=self.n_jobs,
backend="threading")(
delayed(getattr)(tree, 'feature_importances_')
for tree in self.estimators_)
return sum(all_importances) / len(self.estimators_)
|
troubles with pandas anaconda package
Question: I got a new mac and just installed anaconda. When I use `ipython` and
`spyder`, I can `import pandas` without any problem. However, when I use
`sublime`, I get the error
ImportError: No module named pandas
`which python` gives `//anaconda/bin/python`. Also, `pandas` is listed in
`conda list`. I am using `Anaconda2 4.1.1` and `python 2.7.12`. Can someone
help?
Answer: Just add these two line in your .bash_profile, (if you are on bash) export
LC_ALL=en_US.UTF-8 export LANG=en_US.UTF-8 and source it, or restart the
terminal. Or if you are using "oh my zsh" shell, then add the lines in .zshrc.
|
Python KMax Pooling (MXNet)
Question: I'm trying to recreate the char-level CNN in [this
paper](https://arxiv.org/pdf/1606.01781v1.pdf) and am a bit stuck at the final
step where I need to create a k-max pooling layer, because I am using MXNet
and it does not have this.
> An important difference is also the introduction of multiple temporal k-max
> pooling layers. This allows to detect the k most important features in a
> sentence, independent of their specific position, preserving their relative
> order.
However, MXNet does have the ability to [add a new-
op](http://mxnet.readthedocs.io/en/latest/how_to/new_op.html) which I have
been trying to do like so (although getting a bit confused with the shape of
the data, given filters and batch-size).
The shape of the data coming in:
128 (min-batch) x 512 (number of filters) x 1 (height) x 125 (width)
The shape of the data coming out (k-max pooling, k = 7):
128 (min-batch) x 512 (number of filters) x 1 (height) x 7 (width)
My idea so far ... :
class KMaxPooling(mx.operator.CustomOp):
def forward(self, is_train, req, in_data, out_data, aux):
# Desired (k=3):
# in_data = np.array([1, 2, 4, 10, 5, 3])
# out_data = [4, 10, 5]
x = in_data[0].asnumpy()
idx = x.argsort()[-k:]
idx.sort(axis=0)
y = x[idx]
However, I'm not sure about several things:
1. How to test whether this works (once I have some complete code)
2. What the dimensions should be? I'm sorting on the last dimension (axis=0)
3. What to do for the backward() function i.e. the gradient propogation
4. Whether this will work with GPU - I'm guessing I will have to rewrite it in C/cuda?
I found this example by someone else for keras (but don't have the rep to
link):
import numpy as np
import theano.tensor as T
from keras.layers.core import MaskedLayer
class KMaxPooling(MaskedLayer):
def __init__(self, pooling_size):
super(MaskedLayer, self).__init__()
self.pooling_size = pooling_size
self.input = T.tensor3()
def get_output_mask(self, train=False):
return None
def get_output(self, train=False):
data = self.get_input(train)
mask = self.get_input_mask(train)
if mask is None:
mask = T.sum(T.ones_like(data), axis=-1)
mask = mask.dimshuffle(0, 1, "x")
masked_data = T.switch(T.eq(mask, 0), -np.inf, data)
result = masked_data[T.arange(masked_data.shape[0]).dimshuffle(0, "x", "x"),
T.sort(T.argsort(masked_data, axis=1)[:, -self.pooling_size:, :], axis=1),
T.arange(masked_data.shape[2]).dimshuffle("x", "x", 0)]
Answer: [Here](https://github.com/CNevd/DeepLearning-
Mxnet/blob/master/DCNN/dcnn_train.py#L15) you have the code in python with
mxnet.
It would be great to have it as well in R.
|
Compute Cost of Kmeans
Question: I am using this
[model](https://github.com/yahoo/lopq/blob/master/python/lopq/model.py), which
is not written by me. In order to predict the centroids I had to do this:
model = cPickle.load(open("/tmp/model_centroids_128d_pkl.lopq"))
codes = d.map(lambda x: (x[0], model.predict_coarse(x[1])))
where `d.first()' yields this:
(u'3768915289',
array([ -86.00641097, -100.41325623, <128 coords in total>]))
and `codes.first()`:
(u'3768915289', (5657, 7810))
How can I
[computeCost()](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeansModel.computeCost)
of this KMeans model?
* * *
After reading
[train_model.py](https://github.com/yahoo/lopq/blob/master/spark/train_model.py),
I am trying like this:
In [23]: from pyspark.mllib.clustering import KMeans, KMeansModel
In [24]: Cs = model.Cs # centroids
In [25]: model = KMeansModel(Cs[0]) # I am very positive this line is good
In [26]: costs = d.map(lambda x: model.computeCost(x[1]))
In [27]: costs.first()
but I get this error:
AttributeError: 'numpy.ndarray' object has no attribute 'map'
which means that Spark tries to use `map()` under the hood for `x[1]`...
* * *
which means that it expects an RDD!!! But of which form?
I am trying now with:
d = d.map(lambda x: x[1])
d.first()
array([ 7.17036494e+01, 1.07987890e+01, ...])
costs = model.computeCost(d)
and I don't get the error:
16/08/30 00:39:21 WARN TaskSetManager: Lost task 821.0 in stage 40.0 : java.lang.IllegalArgumentException: requirement failed
at scala.Predef$.require(Predef.scala:221)
at org.apache.spark.mllib.util.MLUtils$.fastSquaredDistance(MLUtils.scala:330)
at org.apache.spark.mllib.clustering.KMeans$.fastSquaredDistance(KMeans.scala:595)
at org.apache.spark.mllib.clustering.KMeans$$anonfun$findClosest$1.apply(KMeans.scala:569)
at org.apache.spark.mllib.clustering.KMeans$$anonfun$findClosest$1.apply(KMeans.scala:563)
at scala.collection.mutable.ArraySeq.foreach(ArraySeq.scala:73)
at org.apache.spark.mllib.clustering.KMeans$.findClosest(KMeans.scala:563)
at org.apache.spark.mllib.clustering.KMeans$.pointCost(KMeans.scala:586)
at org.apache.spark.mllib.clustering.KMeansModel$$anonfun$computeCost$1.apply(KMeansModel.scala:88)
at org.apache.spark.mllib.clustering.KMeansModel$$anonfun$computeCost$1.apply(KMeansModel.scala:88)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.foldLeft(TraversableOnce.scala:144)
at scala.collection.AbstractIterator.foldLeft(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.fold(TraversableOnce.scala:199)
at scala.collection.AbstractIterator.fold(Iterator.scala:1157)
at org.apache.spark.rdd.RDD$$anonfun$fold$1$$anonfun$19.apply(RDD.scala:1086)
at org.apache.spark.rdd.RDD$$anonfun$fold$1$$anonfun$19.apply(RDD.scala:1086)
at org.apache.spark.SparkContext$$anonfun$36.apply(SparkContext.scala:1951)
at org.apache.spark.SparkContext$$anonfun$36.apply(SparkContext.scala:1951)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
at org.apache.spark.scheduler.Task.run(Task.scala:89)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:227)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
---------------------------------------------------------------------------
Py4JJavaError Traceback (most recent call last)
<ipython-input-44-6223595c8b5f> in <module>()
----> 1 costs = model.computeCost(d)
/home/gs/spark/current/python/pyspark/mllib/clustering.py in computeCost(self, rdd)
140 """
141 cost = callMLlibFunc("computeCostKmeansModel", rdd.map(_convert_to_vector),
--> 142 [_convert_to_vector(c) for c in self.centers])
143 return cost
144
/home/gs/spark/current/python/pyspark/mllib/common.py in callMLlibFunc(name, *args)
128 sc = SparkContext.getOrCreate()
129 api = getattr(sc._jvm.PythonMLLibAPI(), name)
--> 130 return callJavaFunc(sc, api, *args)
131
132
/home/gs/spark/current/python/pyspark/mllib/common.py in callJavaFunc(sc, func, *args)
121 """ Call Java Function """
122 args = [_py2java(sc, a) for a in args]
--> 123 return _java2py(sc, func(*args))
124
125
/home/gs/spark/current/python/lib/py4j-0.9-src.zip/py4j/java_gateway.py in __call__(self, *args)
811 answer = self.gateway_client.send_command(command)
812 return_value = get_return_value(
--> 813 answer, self.gateway_client, self.target_id, self.name)
814
815 for temp_arg in temp_args:
/home/gs/spark/current/python/pyspark/sql/utils.py in deco(*a, **kw)
43 def deco(*a, **kw):
44 try:
---> 45 return f(*a, **kw)
46 except py4j.protocol.Py4JJavaError as e:
47 s = e.java_exception.toString()
/home/gs/spark/current/python/lib/py4j-0.9-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
306 raise Py4JJavaError(
307 "An error occurred while calling {0}{1}{2}.\n".
--> 308 format(target_id, ".", name), value)
309 else:
310 raise Py4JError(
Py4JJavaError: An error occurred while calling o25177.computeCostKmeansModel.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 821 in stage 40.0 failed 4 times, most recent failure: Lost task 821.3 in stage 40.0: java.lang.IllegalArgumentException: requirement failed
at scala.Predef$.require(Predef.scala:221)
at org.apache.spark.mllib.util.MLUtils$.fastSquaredDistance(MLUtils.scala:330)
at org.apache.spark.mllib.clustering.KMeans$.fastSquaredDistance(KMeans.scala:595)
at org.apache.spark.mllib.clustering.KMeans$$anonfun$findClosest$1.apply(KMeans.scala:569)
at org.apache.spark.mllib.clustering.KMeans$$anonfun$findClosest$1.apply(KMeans.scala:563)
at scala.collection.mutable.ArraySeq.foreach(ArraySeq.scala:73)
at org.apache.spark.mllib.clustering.KMeans$.findClosest(KMeans.scala:563)
at org.apache.spark.mllib.clustering.KMeans$.pointCost(KMeans.scala:586)
at org.apache.spark.mllib.clustering.KMeansModel$$anonfun$computeCost$1.apply(KMeansModel.scala:88)
at org.apache.spark.mllib.clustering.KMeansModel$$anonfun$computeCost$1.apply(KMeansModel.scala:88)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.foldLeft(TraversableOnce.scala:144)
at scala.collection.AbstractIterator.foldLeft(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.fold(TraversableOnce.scala:199)
at scala.collection.AbstractIterator.fold(Iterator.scala:1157)
at org.apache.spark.rdd.RDD$$anonfun$fold$1$$anonfun$19.apply(RDD.scala:1086)
at org.apache.spark.rdd.RDD$$anonfun$fold$1$$anonfun$19.apply(RDD.scala:1086)
at org.apache.spark.SparkContext$$anonfun$36.apply(SparkContext.scala:1951)
at org.apache.spark.SparkContext$$anonfun$36.apply(SparkContext.scala:1951)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
at org.apache.spark.scheduler.Task.run(Task.scala:89)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:227)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
* * *
Edit:
split_vecs = d.map(lambda x: np.split(x[1], 2))
seems to be a good step, since the centroids are of 64 dimensions.
model.computeCost((d.map(lambda x: x[1])).first())
gives this error: `AttributeError: 'numpy.ndarray' object has no attribute
'map'`.
Answer: Apparently from the
[documentation](https://spark.apache.org/docs/latest/mllib-clustering.html)
I've read, you have to:
1. Create a model maybe by [reading](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeansModel.load) a previously [saved ](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeansModel.save) model, or by fitting a new model.
2. After obtaining that [model](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeansModel) you can use its method [computeCost](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeansModel.clusterCenters), which needs a well formatted `RDD` to output something useful.
Thus, if I assume that your variable `model` is a `KMeansModel` and the data
stored in the variable `d` has the expected representation, then you should be
able to run the following code:
model.computeCost(d)
* * *
Edit:
You should create an RDD that will contain vectors of the same dimensions as
the centroids, and provide that as an input parameter to `computeCost()`, like
this for example:
split_vecs = d.map(lambda x: (x[0], np.split(x[1], 2)))
costs_per_split = [KMeansModel(model.Cs[i]).computeCost(split_vecs.map(lambda x: x[1][i])) for i in range(2)]
|
Python dictionary converting to json or yaml
Question: I have parsed a string and converted into a dictionary. however I would like
to be able to get more information from my dictionary and I was thinking
creating a son file or yaml file would be more useful. please feel free to
comment on another way of solving this problem.
import re
regex = '(\w+) \[(.*?)\] "(.*?)" (\d+) "(.*?)" "(.*?)"'
sample2= 'this [condo] "number is" 28 "owned by" "james"'
patern = '(?P<host>\S+)\s(?P<tipe>\[\w+\])\s(?P<txt>"(.*?))\s(?P<number>\d+)\s(?P<txt1>"\w+\s\w+")\s(?P<owner>"\w+)'
m =re.match(patern, sample2)
res = m.groupdict()
print res
and I would get:
{'tipe': '[condo]', 'number': '28', 'host': 'this', 'owner': '"james', 'txt': '"number is"', 'txt1': '"owned by"'}
I would like to be able to sort by owner name and write out the type of house
and the house number. for example:
James:{ type:condo, number: 28}
or any other suggestions?
Answer: The question of json vs yaml boils down to what are you doing with the data
you are saving? If you are reusing the data in JS or in another python script
then you could use JSON. If you were using it in something that uses YAML then
use YAML. But in terms of your question, unless there is a particular end game
or use case for your data, it doesn't matter the format, you could even just
do a typical TSV/CSV and it'd be the same.
To answer your question about how to make a dict in to a json.
From your example once you have the `res` dictionary made.
import json
with open('someFile.json', 'wb') as outfile:
json.dump(res, outfile)
Your output file `someFile.json` will be your dictionary `res`
|
Grouping of documents having the same phone number
Question: My database consists of collection of a large no. of hotels (approx 121,000).
This is how my collection looks like :
{
"_id" : ObjectId("57bd5108f4733211b61217fa"),
"autoid" : 1,
"parentid" : "P01982.01982.110601173548.N2C5",
"companyname" : "Sheldan Holiday Home",
"latitude" : 34.169552,
"longitude" : 77.579315,
"state" : "JAMMU AND KASHMIR",
"city" : "LEH Ladakh",
"pincode" : 194101,
"phone_search" : "9419179870|253013",
"address" : "Sheldan Holiday Home|Changspa|Leh Ladakh-194101|LEH Ladakh|JAMMU AND KASHMIR",
"email" : "",
"website" : "",
"national_catidlineage_search" : "/10255012/|/10255031/|/10255037/|/10238369/|/10238380/|/10238373/",
"area" : "Leh Ladakh",
"data_city" : "Leh Ladakh"
}
Each document can have 1 or more phone numbers separated by "|" delimiter.
I have to group together documents having same phone number.
By real time, I mean when a user opens up a particular hotel to see its
details on the web interface, I should be able to display all the hotels
linked to it grouped by common phone numbers.
While grouping, if one hotel links to another and that hotels links to
another, then all 3 should be grouped together.
> Example : Hotel A has phone numbers 1|2, B has phone numbers 3|4 and C has
> phone numbers 2|3, then A, B and C should be grouped together.
from pymongo import MongoClient
from pprint import pprint #Pretty print
import re #for regex
#import unicodedata
client = MongoClient()
cLen = 0
cLenAll = 0
flag = 0
countA = 0
countB = 0
list = []
allHotels = []
conContact = []
conId = []
hotelTotal = []
splitListAll = []
contactChk = []
#We'll be passing the value later as parameter via a function call
#hId = 37443;
regx = re.compile("^Vivanta", re.IGNORECASE)
#Connection
db = client.hotel
collection = db.hotelData
#Finding hotels wrt search input
for post in collection.find({"companyname":regx}):
list.append(post)
#Copying all hotels in a list
for post1 in collection.find():
allHotels.append(post1)
hotelIndex = 11 #Index of hotel selected from search result
conIndex = hotelIndex
x = list[hotelIndex]["companyname"] #Name of selected hotel
y = list[hotelIndex]["phone_search"] #Phone numbers of selected hotel
try:
splitList = y.split("|") #Splitting of phone numbers and storing in a list 'splitList'
except:
splitList = y
print "Contact details of",x,":"
#Printing all contacts...
for contact in splitList:
print contact
conContact.extend(contact)
cLen = cLen+1
print "No. of contacts in",x,"=",cLen
for i in allHotels:
yAll = allHotels[countA]["phone_search"]
try:
splitListAll.append(yAll.split("|"))
countA = countA+1
except:
splitListAll.append(yAll)
countA = countA + 1
# print splitListAll
#count = 0
#This block has errors
#Add code to stop when no new links occur and optimize the outer for loop
#for j in allHotels:
for contactAll in splitListAll:
if contactAll in conContact:
conContact.extend(contactAll)
# contactChk = contactAll
# if (set(conContact) & set(contactChk)):
# conContact = contactChk
# contactChk[:] = [] #drop contactChk list
conId = allHotels[countB]["autoid"]
countB = countB+1
print "Printing the list of connected hotels..."
for final in collection.find({"autoid":conId}):
print final
This is one code I wrote in Python. In this one, I tried performing linear
search in a for loop. I am getting some errors as of now but it should work
when rectified.
I need an optimized version of this as liner search has poor time complexity.
I am pretty new to this so any other suggestions to improve the code are
welcome.
Thanks.
Answer: The easiest answer to any Python in-memory search-for question is "use a
dict". Dicts give O(ln N) key-access speed, lists give O(N).
Also remember that you can put a Python object into as many dicts (or lists),
and as many times into one dict or list, as it takes. They are not copied.
It's just a reference.
So the essentials will look like
for hotel in hotels:
phones = hotel["phone_search"].split("|")
for phone in phones:
hotelsbyphone.setdefault(phone,[]).append(hotel)
At the end of this loop, `hotelsbyphone["123456"]` will be a list of hotel
objects which had "123456" as one of their `phone_search` strings. The key
coding feature is the `.setdefault(key, [])` method which initializes an empty
list if the key is not already in the dict, so that you can then append to it.
Once you have built this index, this will be fast
try:
hotels = hotelsbyphone[x]
# and process a list of one or more hotels
except KeyError:
# no hotels exist with that number
Alternatively to `try ... except`, test `if x in hotelsbyphone:`
|
pdf_multivariate_gauss() function in Python
Question: Which are the necessary modules for execution of the function
pdf_multivariate_gauss() in IPython?
I try to execute the below code but i get errors like "Import Error" and "Name
Error".
**_Code:_**
import numpy as np
from matplotlib import pyplot as plt
from matplotlib.mlab import bivariate_normal
import parzen_window_est
import pdf_multivariate_gauss ######## ImportError ########
import operator
from mpl_toolkits.mplot3d import Axes3D
##############################################
### Predicted bivariate Gaussian densities ###
##############################################
mu_vec = np.array([0,0])
cov_mat = np.array([[1,0],[0,1]])
x_2Dgauss = np.random.multivariate_normal(mu_vec, cov_mat, 10000)
# generate a range of 400 window widths between 0 < h < 1
h_range = np.linspace(0.001, 1, 400)
# calculate the actual density at the center [0, 0]
mu = np.array([[0],[0]])
cov = np.eye(2)
actual_pdf_val = pdf_multivariate_gauss.pdf_multivariate_gauss(np.array([[0],[0]]), mu, cov)
######## NameError #########
# get a list of the differnces (|estimate-actual|) for different window widths
parzen_estimates = [np.abs(parzen_window_est.parzen_window_est(x_2Dgauss, h=1, center=[0, 0])) for i in h_range]
# get the window width for which |estimate-actual| is closest to 0
min_index, min_value = min(enumerate(parzen_estimates), key=operator.itemgetter(1))
[IPython output](http://i.stack.imgur.com/uqWUp.png)
Answer: As far as I can tell, there is no such thing as pdf_multivariate_gauss (as
pointed out already). There is a python implementation of this in `scipy`,
however:
[scipy.stats.multivariate_normal](http://docs.scipy.org/doc/scipy-0.18.0/reference/generated/scipy.stats.multivariate_normal.html)
One would use it like this:
from scipy.stats import multivariate_normal
mvn = multivariate_normal(mu,cov) #create a multivariate Gaussian object with specified mean and covariance matrix
p = mvn.pdf(x) #evaluate the probability density at x
|
How to execute set of commands after sudo using python script
Question: I am trying to automate deployment process using the python. In deployment I
do "dzdo su - sysid" first and then perform the deployment process. But I am
not able to handle this part in python. I have done similar thing in shell
where I used following piece of code,
/bin/bash
psh su - sysid << EOF
. /users/home/sysid/.bashrc
./deployment.sh
EOF
this handles execution of deployment.sh very well. It does the sudo and then
execute the script with sysid id. I am trying to do similar thing using python
but I am not able to find any alternative to << EOF in python.
I am using subprocess.Popen to execute dzdo part, it does the dzdo, but when I
try to execute next command for e.g. say "ls -l", then this command will not
get executed with the sysid, instead, i had to exit from sysid session and as
soon as i exit, it will execute "ls -l" in my home directory which is of no
use. Can someone please help me on this?
And one more thing, in this case I am not calling any deployment.sh but I will
call commands like cp, rm, mkdir etc.
Answer: The text between `<< EOF` and `EOF` in your shell script example will be
written to the standard input of the `psh` process. So you have to redirect
the standard input of your `Popen` instance and write the data either directly
into the `stdin` file of your instance or use the `communicate()` method:
#!/usr/bin/env python
# coding: utf8
from __future__ import absolute_import, division, print_function
from subprocess import Popen, PIPE
SHELL_COMMANDS = r'''\
. /users/home/sysid/.bashrc
./deployment.sh
'''
def main():
process = Popen(['psh', 'su', '-', 'sysid'], stdin=PIPE)
process.communicate(SHELL_COMMANDS)
if __name__ == '__main__':
main()
If you need the output of the process' stdandard output and/or error then you
need to pipe those too and work with the return value of the `communicate()`
call.
|
Python Import Text Array with Numpy
Question: I have a text file that looks like this:
...
5 [0, 1] [512, 479] 991
10 [1, 0] [706, 280] 986
15 [1, 0] [807, 175] 982
20 [1, 0] [895, 92] 987
...
Each column is tab separated, but there are arrays in some of the columns. Can
I import these with `np.genfromtxt` in some way?
The resulting unpacked lists should be, for example:
data1 = [..., 5, 10, 15, 20, ...]
data2 = [..., [512, 479], [706, 280], ... ] (i.e. a 2D list)
etc.
I tried
`data1, data2, data3, data4 = np.genfromtxt('data.txt', dtype=None,
delimiter='\t', unpack=True)`
but `data2` and `data3` are lists containing 'nan'.
Answer: Potential approach for given data, however not using numpy:
import ast
data1, data2, data3, data4 = [],[],[],[]
for l in open('data.txt'):
data = l.split('\t')
data1.append(int(data[0]))
data2.append(ast.literal_eval(data[1]))
data3.append(ast.literal_eval(data[2]))
data4.append(int(data[3]))
print 'data1', data1
print 'data2', data2
print 'data3', data3
print 'data4', data4
Gives
"data1 [5, 10, 15, 20]"
"data2 [[0, 1], [1, 0], [1, 0], [1, 0]]"
"data3 [[512, 479], [706, 280], [807, 175], [895, 92]]"
"data4 [991, 986, 982, 987]"
|
Retrieve geocodes from Google API and append to original table - python
Question: I am trying to retrieve the geocodes of a bunch of addresses through the
Google geocoding API and append them to my table with addresses.
After spending two days reviewing the internet I coulndΒ΄t find any simple way
of doing while it shouldnΒ΄t be that hard. I am specially having problems
parsing the json output and append it to my original table. I use python 3.5
on windows
I originally got the data from a database which I added to a dataframe in
python. But to paste it here it was easier to convert it to a dictionary and
back to a dataframe:
data_dict={'street': {0: 'ROMULO', 1: 'SAN BARTOLOME', 2: 'GARBI', 3: 'SAN JOSE'},
'concat': {0: '3+ROMULO+CALLE+ALMERIA',
1: '5+SAN BARTOLOME+CALLE+TOLEDO',
2: '48+GARBI+CALLE+CASTELLON',
3: '30+SAN JOSE+CALLE+SANTA CRUZ DE TENERIFE'},
'number': {0: '3', 1: '5', 2: '48', 3: '30'},
'province': {0: 'ALMERIA',
1: 'TOLEDO',
2: 'CASTELLON',
3: 'SANTA CRUZ DE TENERIFE'},
'region': {0: 'ANDALUCIA',
1: 'CASTILLA LA MANCHA',
2: 'COMUNIDAD VALENCIANA',
3: 'CANARIAS'}}
Back to dataframe:
import pandas as pd
table=pd.DataFrame.from_dict(data_dict)
Now I retrieve the data from the Google geocoding API:
import requests
import json
key="MyKey"
jsonout=[]
for i in table.loc[:,'concat']:
try:
url="https://maps.googleapis.com/maps/api/geocode/json?address=%s&key=%s" % (i, key)
response = requests.get(url)
jsonf = response.json()
jsonout.append(jsonf)
except Exception:
continue
I get this output:
jsonout=[{'results': [{'address_components': [{'long_name': '3',
'short_name': '3',
'types': ['street_number']},
{'long_name': 'Calle RΓ³mulo',
'short_name': 'Calle RΓ³mulo',
'types': ['route']},
{'long_name': 'Adra',
'short_name': 'Adra',
'types': ['locality', 'political']},
{'long_name': 'AlmerΓa',
'short_name': 'AL',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'AndalucΓa',
'short_name': 'AL',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '04770', 'short_name': '04770', 'types': ['postal_code']}],
'formatted_address': 'Calle RΓ³mulo, 3, 04770 Adra, AlmerΓa, Spain',
'geometry': {'location': {'lat': 36.7593, 'lng': -2.97818},
'location_type': 'ROOFTOP',
'viewport': {'northeast': {'lat': 36.76064898029149,
'lng': -2.976831019708498},
'southwest': {'lat': 36.7579510197085, 'lng': -2.979528980291502}}},
'partial_match': True,
'place_id': 'ChIJG39VNzNOcA0R2f8Ek3E12AY',
'types': ['street_address']}],
'status': 'OK'},
{'results': [{'address_components': [{'long_name': '5',
'short_name': '5',
'types': ['street_number']},
{'long_name': 'Calle de San BartolomΓ©',
'short_name': 'Calle de San BartolomΓ©',
'types': ['route']},
{'long_name': 'Toledo',
'short_name': 'Toledo',
'types': ['locality', 'political']},
{'long_name': 'Toledo',
'short_name': 'TO',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'Castilla-La Mancha',
'short_name': 'CM',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '45002', 'short_name': '45002', 'types': ['postal_code']}],
'formatted_address': 'Calle de San BartolomΓ©, 5, 45002 Toledo, Spain',
'geometry': {'location': {'lat': 39.8549781, 'lng': -4.026267199999999},
'location_type': 'ROOFTOP',
'viewport': {'northeast': {'lat': 39.85632708029149,
'lng': -4.024918219708497},
'southwest': {'lat': 39.85362911970849, 'lng': -4.027616180291502}}},
'partial_match': True,
'place_id': 'ChIJ4bse1aALag0RJ5RxxfyDxUI',
'types': ['street_address']}],
'status': 'OK'},
{'results': [{'address_components': [{'long_name': '48',
'short_name': '48',
'types': ['street_number']},
{'long_name': 'Carrer de GarbΓ',
'short_name': 'Carrer de GarbΓ',
'types': ['route']},
{'long_name': 'PenΓscola',
'short_name': 'PenΓscola',
'types': ['locality', 'political']},
{'long_name': 'CastellΓ³',
'short_name': 'CastellΓ³',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'Comunidad Valenciana',
'short_name': 'Comunidad Valenciana',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '12598', 'short_name': '12598', 'types': ['postal_code']}],
'formatted_address': 'Carrer de GarbΓ, 48, 12598 PenΓscola, CastellΓ³, Spain',
'geometry': {'location': {'lat': 40.3634529, 'lng': 0.3963583},
'location_type': 'ROOFTOP',
'viewport': {'northeast': {'lat': 40.3648018802915,
'lng': 0.397707280291502},
'southwest': {'lat': 40.3621039197085, 'lng': 0.395009319708498}}},
'partial_match': True,
'place_id': 'ChIJHVNHcelGoBIRogILRMno_wk',
'types': ['street_address']},
{'address_components': [{'long_name': '48',
'short_name': '48',
'types': ['street_number']},
{'long_name': 'Carrer GarbΓ',
'short_name': 'Carrer GarbΓ',
'types': ['route']},
{'long_name': 'Vila-real',
'short_name': 'Vila-real',
'types': ['locality', 'political']},
{'long_name': 'CastellΓ³',
'short_name': 'CastellΓ³',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'Comunidad Valenciana',
'short_name': 'Comunidad Valenciana',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '12540', 'short_name': '12540', 'types': ['postal_code']}],
'formatted_address': 'Carrer GarbΓ, 48, 12540 Vila-real, CastellΓ³, Spain',
'geometry': {'bounds': {'northeast': {'lat': 39.955829, 'lng': -0.110409},
'southwest': {'lat': 39.9558231, 'lng': -0.1104261}},
'location': {'lat': 39.9558231, 'lng': -0.110409},
'location_type': 'RANGE_INTERPOLATED',
'viewport': {'northeast': {'lat': 39.9571750302915,
'lng': -0.109068569708498},
'southwest': {'lat': 39.9544770697085, 'lng': -0.111766530291502}}},
'partial_match': True,
'place_id': 'EjRDYXJyZXIgR2FyYsOtLCA0OCwgMTI1NDAgVmlsYS1yZWFsLCBDYXN0ZWxsw7MsIFNwYWlu',
'types': ['street_address']}],
'status': 'OK'},
{'results': [{'address_components': [{'long_name': '30',
'short_name': '30',
'types': ['street_number']},
{'long_name': 'Calle San JosΓ©',
'short_name': 'Calle San JosΓ©',
'types': ['route']},
{'long_name': 'Santa Cruz de la Palma',
'short_name': 'Santa Cruz de la Palma',
'types': ['locality', 'political']},
{'long_name': 'Santa Cruz de Tenerife',
'short_name': 'TF',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'Canarias',
'short_name': 'CN',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '38700', 'short_name': '38700', 'types': ['postal_code']}],
'formatted_address': 'Calle San JosΓ©, 30, 38700 Santa Cruz de la Palma, Santa Cruz de Tenerife, Spain',
'geometry': {'location': {'lat': 28.6864347, 'lng': -17.7624433},
'location_type': 'ROOFTOP',
'viewport': {'northeast': {'lat': 28.6877836802915,
'lng': -17.7610943197085},
'southwest': {'lat': 28.6850857197085, 'lng': -17.7637922802915}}},
'partial_match': True,
'place_id': 'ChIJ8ZFx6__rawwRV3dc118gEgE',
'types': ['street_address']},
{'address_components': [{'long_name': '30',
'short_name': '30',
'types': ['street_number']},
{'long_name': 'Calle San JosΓ©',
'short_name': 'Calle San JosΓ©',
'types': ['route']},
{'long_name': 'San AndrΓ©s',
'short_name': 'San AndrΓ©s',
'types': ['locality', 'political']},
{'long_name': 'Santa Cruz de Tenerife',
'short_name': 'Santa Cruz de Tenerife',
'types': ['administrative_area_level_4', 'political']},
{'long_name': 'Santa Cruz de Tenerife',
'short_name': 'TF',
'types': ['administrative_area_level_2', 'political']},
{'long_name': 'Canarias',
'short_name': 'CN',
'types': ['administrative_area_level_1', 'political']},
{'long_name': 'Spain',
'short_name': 'ES',
'types': ['country', 'political']},
{'long_name': '38120', 'short_name': '38120', 'types': ['postal_code']}],
'formatted_address': 'Calle San JosΓ©, 30, 38120 San AndrΓ©s, Santa Cruz de Tenerife, Spain',
'geometry': {'location': {'lat': 28.505875, 'lng': -16.1930036},
'location_type': 'ROOFTOP',
'viewport': {'northeast': {'lat': 28.5072239802915,
'lng': -16.1916546197085},
'southwest': {'lat': 28.5045260197085, 'lng': -16.1943525802915}}},
'partial_match': True,
'place_id': 'ChIJsfd-ITjKQQwRjFHLI0XPSok',
'types': ['street_address']}],
'status': 'OK'}]
What I finally would like to have is my original table dataframe with the lat
and lng coordinates
(i['results'][0]['geometry']['location']['lat'],
i['results'][0]['geometry']['location']['lng'])
and the formatted_address from the request.
Answer: I use [this package](https://pypi.python.org/pypi/geopy) to do my geocoding,
which takes care of parsing the JSON file.
from geopy.geocoders import GoogleV3
googleGeo = GoogleV3('googleKey')
# create a geocoded list containing geocode objects
geocoded = []
for address in mydata['location']: # assumes mydata is a pandas df
geocoded.append(googleGeo.geocode(address)) # geocode function returns a geocoded object
# append geocoded list to mydata
mydata['geocoded'] = geocoded
# create coordinates column
mydata['coords'] = mydata['geocoded'].apply(lambda x: (x.latitude, x.longitude))
# if you want to split our your lat and long then do
# mydata['lat'] = mydata['geocoded'].apply(lambda x: x.latitude)
# mydata['long'] = mydata['geocoded'].apply(lambda x: x.longitude)
* * *
Based on the comment you shared, if you are using Google's API without an API
key, then it might be beneficial to include a random pause between each
geocode call.
from time import sleep
from random import randint
from geopy.geocoders import GoogleV3
googleGeo = GoogleV3()
def geocode(address):
location = googleGeo.geocode(address)
sleep(randint(5,10)) # give the API a break
return location
Then you use this custom function to do your geocoding
* * *
Piggybacking on my earlier section, you can even utilize multiple map API
services. This is the function I built for one of my projects, utilizing
Nominatim's API first, and then falling back on Google's API if Nominatim
either returns an error or returns nothing:
from geopy.geocoders import Nominatim, GoogleV3
from geopy.exc import GeocoderTimedOut, GeocoderAuthenticationFailure
from random import randint
from time import sleep
nomiGeo = Nominatim() # Nominatim geolocator
googleGeo = GoogleV3('myKey') # Google Maps v3 API geolocator
def geocode(address):
"""Geocode an address.
Args:
address (str): the physical address
Returns:
dict: geocoded object
"""
location = None
attempt = 0
useGoogle = False # set to True to use Google only
while (location is None) and (attempt <= 8):
try:
attempt += 1
if useGoogle:
location = googleGeo.geocode(address, timeout=10)
else:
location = nomiGeo.geocode(address, timeout=10)
if location is None:
useGoogle = True
location = googleGeo.geocode(address, timeout=10)
sleep(randint(5, 10)) # Give the API a break
except GeocoderAuthenticationFailure:
print 'Error: GeocoderAuthenticationFailure while geocoding {} during attempt #{}'.format(address, attempt)
if attempt % 2 == 0: # switch between services for every attempt
useGoogle = True
else:
useGoogle = False
sleep(60)
except GeocoderTimedOut:
sleep(randint(3, 5)) # Give API a break
print 'Error: GeocoderTimedOut while geocoding {} during attempt #{}'.format(address, attempt)
return location
Note that I also imported some exceptions specific to the package, because
based on my experience with Nominatim, it can sometimes throw random errors
and these were the two that I got. Also, from my experiences with the two
APIs, Google seemed to be able to interpolate coordinates even if a certain
address was not found, whereas Nominatim had to have the address in their
database in order to return something.
|
Why my Element not in view when page scrolls by itself in selenium?
Question: Now, suppose my page have 10 clickable links with same class, one below
another at some distance, such that only 1st 3 links are shown in current
view, others are seen when i scroll down. Now, i have written a code to click
on all of them. It clicks on first 3 and then selenium scrolls my page to show
link 5 to 7, page is scrolling too much so as not to show link 4 and since
code is trying to click link 4 which is not visible, my code gives error-
Element is not visible.
Code:
def AddConnection(self):
mylist=self.driver.find_elements_by_xpath("//a[@class='primary-action-button label']")
for x in mylist:
x.click()
Full Error:
================================== FAILURES ===================================
_____________________________ test_add_connection _____________________________
driver = <selenium.webdriver.firefox.webdriver.WebDriver (session="3a05990c-13b
-4418-baee-f0d54c611ff7")>
> add.AddConnection()
test_add_connection.py:22:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
PageSearchResults.py:24: in AddConnection
x.click()
c:\python27\lib\site-packages\selenium\webdriver\remote\webelement.py:73: in cl
ck
self._execute(Command.CLICK_ELEMENT)
c:\python27\lib\site-packages\selenium\webdriver\remote\webelement.py:456: in _
xecute
return self._parent.execute(command, params)
c:\python27\lib\site-packages\selenium\webdriver\remote\webdriver.py:236: in ex
cute
self.error_handler.check_response(response)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = <selenium.webdriver.remote.errorhandler.ErrorHandler object at 0x01E6ACB
>
response = {'status': 500, 'value': '{"name":"clickElement","sessionId":"3a0599
c-13b8-4418-baee-f0d54c611ff7","status":13,"value...int (892.5, 12.199996948242
88). Other element would receive the click: <div class=\"advanced-search-inner\
></div>"}'}
def check_response(self, response):
"""
Checks that a JSON response from the WebDriver does not have an err
r.
:Args:
- response - The JSON response from the WebDriver server as a dict
onary
object.
:Raises: If the response contains an error message.
"""
status = response.get('status', None)
if status is None or status == ErrorCode.SUCCESS:
return
value = None
message = response.get("message", "")
screen = response.get("screen", "")
stacktrace = None
if isinstance(status, int):
value_json = response.get('value', None)
if value_json and isinstance(value_json, basestring):
import json
try:
value = json.loads(value_json)
status = value.get('error', None)
if status is None:
status = value["status"]
message = value["value"]
if not isinstance(message, basestring):
value = message
try:
message = message['message']
except TypeError:
message = None
else:
message = value.get('message', None)
except ValueError:
pass
exception_class = ErrorInResponseException
if status in ErrorCode.NO_SUCH_ELEMENT:
exception_class = NoSuchElementException
elif status in ErrorCode.NO_SUCH_FRAME:
exception_class = NoSuchFrameException
elif status in ErrorCode.NO_SUCH_WINDOW:
exception_class = NoSuchWindowException
elif status in ErrorCode.STALE_ELEMENT_REFERENCE:
exception_class = StaleElementReferenceException
elif status in ErrorCode.ELEMENT_NOT_VISIBLE:
exception_class = ElementNotVisibleException
elif status in ErrorCode.INVALID_ELEMENT_STATE:
exception_class = InvalidElementStateException
elif status in ErrorCode.INVALID_SELECTOR \
or status in ErrorCode.INVALID_XPATH_SELECTOR \
or status in ErrorCode.INVALID_XPATH_SELECTOR_RETURN_TYPER:
exception_class = InvalidSelectorException
elif status in ErrorCode.ELEMENT_IS_NOT_SELECTABLE:
exception_class = ElementNotSelectableException
elif status in ErrorCode.INVALID_COOKIE_DOMAIN:
exception_class = WebDriverException
elif status in ErrorCode.UNABLE_TO_SET_COOKIE:
exception_class = WebDriverException
elif status in ErrorCode.TIMEOUT:
exception_class = TimeoutException
elif status in ErrorCode.SCRIPT_TIMEOUT:
exception_class = TimeoutException
elif status in ErrorCode.UNKNOWN_ERROR:
exception_class = WebDriverException
elif status in ErrorCode.UNEXPECTED_ALERT_OPEN:
exception_class = UnexpectedAlertPresentException
elif status in ErrorCode.NO_ALERT_OPEN:
exception_class = NoAlertPresentException
elif status in ErrorCode.IME_NOT_AVAILABLE:
exception_class = ImeNotAvailableException
elif status in ErrorCode.IME_ENGINE_ACTIVATION_FAILED:
exception_class = ImeActivationFailedException
elif status in ErrorCode.MOVE_TARGET_OUT_OF_BOUNDS:
exception_class = MoveTargetOutOfBoundsException
else:
exception_class = WebDriverException
if value == '' or value is None:
value = response['value']
if isinstance(value, basestring):
if exception_class == ErrorInResponseException:
raise exception_class(response, value)
raise exception_class(value)
if message == "" and 'message' in value:
message = value['message']
screen = None
if 'screen' in value:
screen = value['screen']
stacktrace = None
if 'stackTrace' in value and value['stackTrace']:
stacktrace = []
try:
for frame in value['stackTrace']:
line = self._value_or_default(frame, 'lineNumber', '')
file = self._value_or_default(frame, 'fileName', '<anonymou
>')
if line:
file = "%s:%s" % (file, line)
meth = self._value_or_default(frame, 'methodName', '<anonym
us>')
if 'className' in frame:
meth = "%s.%s" % (frame['className'], meth)
msg = " at %s (%s)"
msg = msg % (meth, file)
stacktrace.append(msg)
except TypeError:
pass
if exception_class == ErrorInResponseException:
raise exception_class(response, message)
elif exception_class == UnexpectedAlertPresentException and 'alert' in
alue:
raise exception_class(message, screen, stacktrace, value['alert'].g
t('text'))
> raise exception_class(message, screen, stacktrace)
E WebDriverException: Message: Element is not clickable at point (892.5,
2.199996948242188). Other element would receive the click: <div class="advanced
search-inner"></div>
c:\python27\lib\site-packages\selenium\webdriver\remote\errorhandler.py:194: We
DriverException
========================== 1 failed in 40.13 seconds ==========================
Answer: Figured out the solution, by adding this code after every click.
self.driver.execute_script("window.scrollBy(0, 150);")
|
Python speech recognition error converting mp3 file
Question: My first try on audio to text.
import speech_recognition as sr
r = sr.Recognizer()
with sr.AudioFile("/path/to/.mp3") as source:
audio = r.record(source)
When I execute the above code, the following error occurs,
<ipython-input-10-72e982ecb706> in <module>()
----> 1 with sr.AudioFile("/home/yogaraj/Documents/Python workouts/Python audio to text/show_me_the_meaning.mp3") as source:
2 audio = sr.record(source)
3
/usr/lib/python2.7/site-packages/speech_recognition/__init__.pyc in __enter__(self)
197 aiff_file = io.BytesIO(aiff_data)
198 try:
--> 199 self.audio_reader = aifc.open(aiff_file, "rb")
200 except aifc.Error:
201 assert False, "Audio file could not be read as WAV, AIFF, or FLAC; check if file is corrupted"
/usr/lib64/python2.7/aifc.pyc in open(f, mode)
950 mode = 'rb'
951 if mode in ('r', 'rb'):
--> 952 return Aifc_read(f)
953 elif mode in ('w', 'wb'):
954 return Aifc_write(f)
/usr/lib64/python2.7/aifc.pyc in __init__(self, f)
345 f = __builtin__.open(f, 'rb')
346 # else, assume it is an open file object already
--> 347 self.initfp(f)
348
349 #
/usr/lib64/python2.7/aifc.pyc in initfp(self, file)
296 self._soundpos = 0
297 self._file = file
--> 298 chunk = Chunk(file)
299 if chunk.getname() != 'FORM':
300 raise Error, 'file does not start with FORM id'
/usr/lib64/python2.7/chunk.py in __init__(self, file, align, bigendian, inclheader)
61 self.chunkname = file.read(4)
62 if len(self.chunkname) < 4:
---> 63 raise EOFError
64 try:
65 self.chunksize = struct.unpack(strflag+'L', file.read(4))[0]
I don't know what I'm going wrong. Can someone say me what I'm wrong in the
above code?
Answer: `Speech recognition` supports WAV file format. Here is a sample WAV to text
program using `speech_recognition`:
### Sample code (Python 3)
import speech_recognition as sr
r = sr.Recognizer()
with sr.AudioFile("woman1_wb.wav") as source:
audio = r.record(source)
try:
s = r.recognize_google(audio)
print("Text: "+s)
except Exception as e:
print("Exception: "+str(e))
### Output:
Text: to administer medicine to animals is frequency of very difficult matter and yet sometimes it's necessary to do so
Used WAV File URL: <http://www-
mobile.ecs.soton.ac.uk/hth97r/links/Database/woman1_wb.wav>
|
Python - insert HTML content tp WordPress using xmlrpc api
Question: I'm trying to insert HTML content in my WordPress blog via XMLRPC but if i
insert HTML - i got an error:
> raise TypeError, "cannot marshal %s objects" % type(value) TypeError: cannot
> marshal objects
If i use bleach (for clean tags) - i got text with tags on my page
My code
# coding: utf-8
import requests
from bs4 import BeautifulSoup
import bleach
from wordpress_xmlrpc import Client, WordPressPost
from wordpress_xmlrpc.methods import posts
xmlrpc_url = "http://site.ru/xmlrpc.php"
wp_username = "user"
wp_password = "123"
blog_id = ""
client = Client(xmlrpc_url, wp_username, wp_password, blog_id)
url = "https://lifehacker.ru/2016/08/30/finansovye-sovety-dlya-molodyx-par/"
r = requests.get(url)
soup = BeautifulSoup(r.content)
post_title = soup.find("h1")
post_excerpt = soup.find("div", {"class", "single__excerpt"})
for tag in post_excerpt():
for attribute in ["class", "id", "style"]:
del tag[attribute]
post_content = soup.find("div", {"class","post-content"})
for tag in post_content():
for attribute in ["class", "id", "style"]:
del tag[attribute]
post = WordPressPost()
post.title = post_title.text
post.content = post_content
post.id = client.call(posts.NewPost(post))
post.post_status = 'publish'
client.call(posts.EditPost(post.id, post))
How i can insert parsed HTML content in my WordPress blog?
Answer: Use .replace after bleach and fixed issue.
My code
...
post_content_insert = bleach.clean(post_content)
post_content_insert = post_content_insert.replace('<','<')
post_content_insert = post_content_insert.replace('>','>')
post = WordPressPost()
post.title = post_title.text
post.content = post_content_insert
post.id = client.call(posts.NewPost(post))
|
How do I remove consecutive duplicates from a list?
Question: How do I remove consecutive duplicates from a list like this in python?
lst = [1,2,2,4,4,4,4,1,3,3,3,5,5,5,5,5]
Having a unique list or set wouldn't solve the problem as there are some
repeated values like 1,...,1 in the previous list.
I want the result to be like this:
newlst = [1,2,4,1,3,5]
Would you also please consider the case when I have a list like this `[4, 4,
4, 4, 2, 2, 3, 3, 3, 3, 3, 3]` and I want the result to be `[4,2,3,3]` rather
than `[4,2,3]` .
Answer: [itertools.groupby()](https://docs.python.org/3/library/itertools.html#itertools.groupby)
is your solution.
newlst = [k for k, g in itertools.groupby(lst)]
* * *
If you wish to group and limit the group size by the item's value, meaning 8
4's will be [4,4], and 9 3's will be [3,3,3] here are 2 options that does it:
import itertools
def special_groupby(iterable):
last_element = 0
count = 0
state = False
def key_func(x):
nonlocal last_element
nonlocal count
nonlocal state
if last_element != x or x >= count:
last_element = x
count = 1
state = not state
else:
count += 1
return state
return [next(g) for k, g in itertools.groupby(iterable, key=key_func)]
special_groupby(lst)
OR
def grouper(iterable, n, fillvalue=None):
"Collect data into fixed-length chunks or blocks"
# grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx"
args = [iter(iterable)] * n
return itertools.zip_longest(*args, fillvalue=fillvalue)
newlst = list(itertools.chain.from_iterable(next(zip(*grouper(g, k))) for k, g in itertools.groupby(lst)))
Choose whichever you deem appropriate. Both methods are for numbers > 0.
|
Python Highlight specific text in json document on terminal
Question: I am interested in highlighting a specific portion of the json document based
on some arbitrary matching algorithm. For example
{
"text" : "hello world"
}
I searched for "hello" and above json document has hello in it. How to
highlight that particular portion "hello" while displaying the document on the
terminal using python? Also, the json has to be pretty printed.
Expected
{
"text" : " `hello` world"
}
Text that is qoutes should be displayed in red color.
Answer: I can't comment :(
The answer here might be able to help you: [Print in terminal with colors
using Python?](http://stackoverflow.com/questions/287871/print-in-terminal-
with-colors-using-python)
For example, you could use termcolor (if you are using a linux style terminal)
and replace "hello" with colored("hello", "red")
from termcolor import colored
sample_text = "colored hello there !"
print(sample_text)
print(sample_text.replace("hello", colored("hello", "red")))
|
Server responds by "text/html" to a "text/css" request
Question: **PROBLEM:** When I try to access the web page (localhost/mysite/admin), all
goes well, except the CSS files which my server can't deliver !!
[I got a **500 Internal Server Error**](http://i.stack.imgur.com/0VNcT.png)
[By investigating the problem, I found that the server returns a **text/html**
instead of **text/css**](http://i.stack.imgur.com/s4wTn.png)
**Apache 2.4.23 / mod_wsgi 4.5.5 / Python 3.4.2 / Django 1.8 on Linux Debian
(64-bit)**
Additional informations:
This is my **settings.py** file
"""
Django settings for mysite project.
Generated by 'django-admin startproject' using Django 1.8.
For more information on this file, see
https://docs.djangoproject.com/en/1.8/topics/settings/
For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.8/ref/settings/
"""
# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.8/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '##################################################'
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True
ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls'
)
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'django.middleware.security.SecurityMiddleware',
)
ROOT_URLCONF = 'mysite.urls'
TEMPLATES = [
{
'BACKEND': 'django.template.backends.django.DjangoTemplates',
'DIRS': [os.path.join(BASE_DIR,'templates')],
'APP_DIRS': True,
'OPTIONS': {
'context_processors': [
'django.template.context_processors.debug',
'django.template.context_processors.request',
'django.contrib.auth.context_processors.auth',
'django.contrib.messages.context_processors.messages',
],
},
},
]
WSGI_APPLICATION = 'mysite.wsgi.application'
# Database
# https://docs.djangoproject.com/en/1.8/ref/settings/#databases
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}
# Internationalization
# https://docs.djangoproject.com/en/1.8/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.8/howto/static-files/
STATIC_ROOT = '/var/www/django-projects/mysite/static'
STATIC_URL = '/static/'
The lines wich are appended to the httpd.conf (Apache HTTP Server)
# Enable access for Django website mysite
WSGIScriptAlias /mysite /var/www/django-projects/mysite/mysite/wsgi.py process-group=mysite
WSGIScriptAlias /static /var/www/django-projects/mysite/static process-group=mysite
WSGIPythonPath /var/www/django-projects/mysite:/home/ibrahim/.virtualenvs/django-1.8/lib/python3.4/site-packages
WSGIDaemonProcess mysite python-path=/var/www/django-projects/mysite:/home/ibrahim/.virtualenvs/django-1.8/lib/python3.4/site-packages
WSGIProcessGroup mysite
<Directory /var/www/django-projects/mysite>
Require all granted
Options FollowSymLinks
ServerSignature On
</Directory>
Project structure:
- mysite
- mysite
+ __pycache__
__init__.py
settings.py
urls.py
wsgi.py
- polls
+ __pycache__
+ migrations
__init__.py
admin.py
models.py
tests.py
views.py
- static
- admin
- css
base.css
........
+ img
+ js
+ templates
.schema
db.sqlite3
manage.py
Note that the file `/usr/local/apache2/conf/mime.types` include the following
line: `text/css css`
Answer: @Ankush Raghuvanshi: Yes, it serves all kind of files except CSS ! Also, when
I us the built-in development server (which I run by using the command `python
manage.py runserver` ): these CSS files works fine on my website.
|
Python performance on reading files with extremely long lines
Question: I've got a file with around 6MB of data. All of the data are written in a
single line. Why is the following command taking more than 15 minutes to
finish? Is it normal?
infile = open('file.txt')
outfile = open('out.txt', 'w')
for line in infile.readlines():
outfile.write(line);
**Details:**
I'm using Python 2.7.
Output from **wc** :
* newline count: 2
* word count: 3475246
* byte count: 6951140
**Evaluation 1:**
_Reference_ code using in file (suggestted by Ahsanul Haque and Daewon Lee):
for line in infile:
output.write(line):
_Time: 959.487 secs._
Answer: Try the following code snippet. The `readlines()` loads all data on memory,
which seems to cause a long time.
infile = open('file.txt', 'r')
outfile = open('out.txt', 'w')
for line in infile:
outfile.write(line)
With my python 3.5 (64bit) on Windows 10 OS, the following code snippet
finished within a few seconds.
import time
start = time.time()
with open("huge_text.txt", "w") as fout:
for i in range(1737623):
fout.write("ABCD ")
fout.write('\n')
for i in range(1737623):
fout.write("EFGH ")
fout.write('\n')
# end of with
infile = open('huge_text.txt', 'r')
outfile = open('out.txt', 'w')
for line in infile:
outfile.write(line)
outfile.close()
infile.close()
end = time.time()
print("Time elapsed: ", end - start)
"""
<Output>
Time elapsed: 1.557690143585205
"""
|
python repeat list elements in an iterator
Question: Is there any way to create an iterator to repeat elements in a list certain
times? For example, a list is given:
color = ['r', 'g', 'b']
Is there a way to create a iterator in form of `itertools.repeatlist(color,
7)` that can produce the following list?
color_list = ['r', 'g', 'b', 'r', 'g', 'b', 'r']
Answer: You can use
[`itertools.cycle()`](https://docs.python.org/2/library/itertools.html#itertools.cycle)
together with
[`itertools.islice()`](https://docs.python.org/2/library/itertools.html#itertools.islice)
to build your `repeatlist()` function:
from itertools import cycle, islice
def repeatlist(it, count):
return islice(cycle(it), count)
This returns a new iterator; call `list()` on it if you must have a list
object.
Demo:
>>> from itertools import cycle, islice
>>> def repeatlist(it, count):
... return islice(cycle(it), count)
...
>>> color = ['r', 'g', 'b']
>>> list(repeatlist(color, 7))
['r', 'g', 'b', 'r', 'g', 'b', 'r']
|
Exit a multiprocessing script
Question: I am trying to exit a multiprocessing script when an error is thrown by the
target function, but instead of quitting, the parent process just hangs.
This is the test script I use to replicate the problem:
#!/usr/bin/python3.5
import time, multiprocessing as mp
def myWait(wait, resultQueue):
startedAt = time.strftime("%H:%M:%S", time.localtime())
time.sleep(wait)
endedAt = time.strftime("%H:%M:%S", time.localtime())
name = mp.current_process().name
resultQueue.put((name, wait, startedAt, endedAt))
# queue initialisation
resultQueue = mp.Queue()
# process creation arg: (process number, sleep time, queue)
proc = [
mp.Process(target=myWait, name = ' _One_', args=(2, resultQueue,)),
mp.Process(target=myWait, name = ' _Two_', args=(2, resultQueue,))
]
# starting processes
for p in proc:
p.start()
for p in proc:
p.join()
# print results
results = {}
for p in proc:
name, wait, startedAt, endedAt = resultQueue.get()
print('Process %s started at %s wait %s ended at %s' % (name, startedAt, wait, endedAt))
This works perfectly, I can see the parent script spawning two child processes
in `htop` but when I want to force the parent script to exit if an error is
thrown in the `myWait` target function the parent process just hangs and
doesn't even spawn any child process. I have to `ctrl-c` to kill it.
def myWait(wait, resultQueue):
try:
# do something wrong
except:
raise SystemExit
I have tried every way to exit the function (e.g. `exit()`, `sys.exit()`,
`os._exit()`...) to no avail.
Answer: Firstly, your code has a major issue: you're trying to join the processes
before flushing the content of the queues, if any, which can result in a
deadlock. See the section titled 'Joining processes that use queues' here:
<https://docs.python.org/3/library/multiprocessing.html#multiprocessing-
programming>
Secondly, the call to `resultQueue.get()` will block until it receives some
data, which never happens if an exception is raised from the `myWait` function
and that no data has been pushed into the queue before then. So make it non-
blocking and make it check for any data in a loop until it finally receives
something or that something's wrong.
Here's a quick'n'dirty fix to give you the idea:
#!/usr/bin/python3.5
import multiprocessing as mp
import queue
import time
def myWait(wait, resultQueue):
raise Exception("error!")
# queue initialisation
resultQueue = mp.Queue()
# process creation arg: (process number, sleep time, queue)
proc = [
mp.Process(target=myWait, name = ' _One_', args=(2, resultQueue,)),
mp.Process(target=myWait, name = ' _Two_', args=(2, resultQueue,))
]
# starting processes
for p in proc:
p.start()
# print results
results = {}
for p in proc:
while True:
if not p.is_alive():
break
try:
name, wait, startedAt, endedAt = resultQueue.get(block=False)
print('Process %s started at %s wait %s ended at %s'
% (name, startedAt, wait, endedAt))
break
except queue.Empty:
pass
for p in proc:
p.join()
The function `myWait` will throw an exception but both processes will still
join and the program will exit nicely.
|
ImportError: No module named impyla
Question: I have installed impyla and it's dependencies following
[this](https://github.com/cloudera/impyla) guide. The installation seems to be
successful as now I can see the folder **"impyla-0.13.8-py2.7.egg"** in the
Anaconda folder (64-bit Anaconda 4.1.1 version).
But when I import impyla in python, I get the following error:
>>> import impyla
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named impyla
**I have installed 64-bit Python 2.7.12**
**Can any body please explain me why I am facing this error?** I am new on
Python and have been spending allot of time on different blogs, but I don't
see much information present there yet. Thanks in advance for your time.
Answer: Usage is a little bit different then you mentioned (from
<https://github.com/cloudera/impyla>)
Impyla implements the Python DB API v2.0 (PEP 249) database interface (refer
to it for API details):
from impala.dbapi import connect
conn = connect(host='my.host.com', port=21050)
cursor = conn.cursor()
cursor.execute('SELECT * FROM mytable LIMIT 100')
print cursor.description # prints the result set's schema
results = cursor.fetchall()
The Cursor object also exposes the iterator interface, which is buffered
(controlled by cursor.arraysize):
cursor.execute('SELECT * FROM mytable LIMIT 100')
for row in cursor:
process(row)
You can also get back a pandas DataFrame object
from impala.util import as_pandas
df = as_pandas(cur)
# carry df through scikit-learn, for example
|
I keep getting The below errors on my log file whenever i try to Push my django app to Heroku, Kindly assist on how i should go about in solving it,
Question: Here is my log file
$ python manage.py collectstatic --noinput
Traceback (most recent call last):
File "manage.py", line 9, in <module>
execute_from_command_line(sys.argv)
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/management/__init__.py", line 327, in execute
django.setup()
File "/app/.heroku/python/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
apps.populate(settings.INSTALLED_APPS)
File "/app/.heroku/python/lib/python2.7/site-packages/django/apps/registry.py", line 115, in populate
app_config.ready()
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/apps.py", line 22, in ready
self.module.autodiscover()
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/__init__.py", line 26, in autodiscover
autodiscover_modules('admin', register_to=site)
File "/app/.heroku/python/lib/python2.7/site-packages/django/utils/module_loading.py", line 50, in autodiscover_modules
import_module('%s.%s' % (app_config.name, module_to_search))
File "/app/.heroku/python/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
File "/app/.heroku/python/lib/python2.7/site-packages/registration/admin.py", line 2, in <module>
from django.contrib.sites.models import RequestSite
ImportError: cannot import name RequestSite
! Error while running '$ python manage.py collectstatic --noinput'.
See traceback above for details.
You may need to update application code to resolve this error.
Or, you can disable collectstatic for this application:
$ heroku config:set DISABLE_COLLECTSTATIC=1
https://devcenter.heroku.com/articles/django-assets
! Push rejected, failed to compile Python app.
! Push failed
Answer: RequestSite was moved from django.contrib.sites.models to
django.contrib.sites.requests in Django 1.7, and the alias in models was
removed in Django 1.9. You should ensure you are running a version of django-
registration that is compatible with the version of Django you are using.
|
Using strings and byte-like objects compatibly in code to run in both Python 2 & 3
Question: I'm trying to modify the code shown far below, which works in Python 2.7.x, so
it will also work unchanged in Python 3.x. However I'm encountering the
following problem I can't solve in the first function, `bin_to_float()` as
shown by the output below:
float_to_bin(0.000000): '0'
Traceback (most recent call last):
File "binary-to-a-float-number.py", line 36, in <module>
float = bin_to_float(binary)
File "binary-to-a-float-number.py", line 9, in bin_to_float
return struct.unpack('>d', bf)[0]
TypeError: a bytes-like object is required, not 'str'
I tried to fix that by adding a `bf = bytes(bf)` right before the call to
`struct.unpack()`, but doing so produced its own `TypeError`:
TypeError: string argument without an encoding
So my questions are is it possible to fix this issue and achieve my goal? And
if so, how? Preferably in a way that would work in both versions of Python.
Here's the code that works in Python 2:
import struct
def bin_to_float(b):
""" Convert binary string to a float. """
bf = int_to_bytes(int(b, 2), 8) # 8 bytes needed for IEEE 754 binary64
return struct.unpack('>d', bf)[0]
def int_to_bytes(n, minlen=0): # helper function
""" Int/long to byte string. """
nbits = n.bit_length() + (1 if n < 0 else 0) # plus one for any sign bit
nbytes = (nbits+7) // 8 # number of whole bytes
bytes = []
for _ in range(nbytes):
bytes.append(chr(n & 0xff))
n >>= 8
if minlen > 0 and len(bytes) < minlen: # zero pad?
bytes.extend((minlen-len(bytes)) * '0')
return ''.join(reversed(bytes)) # high bytes at beginning
# tests
def float_to_bin(f):
""" Convert a float into a binary string. """
ba = struct.pack('>d', f)
ba = bytearray(ba)
s = ''.join('{:08b}'.format(b) for b in ba)
s = s.lstrip('0') # strip leading zeros
return s if s else '0' # but leave at least one
for f in 0.0, 1.0, -14.0, 12.546, 3.141593:
binary = float_to_bin(f)
print('float_to_bin(%f): %r' % (f, binary))
float = bin_to_float(binary)
print('bin_to_float(%r): %f' % (binary, float))
print('')
Answer: To make portable code that works with bytes in both Python 2 and 3 using
libraries that literally use the different data types between the two, you
need to explicitly declare them using the appropriate literal mark for every
string (or add [`from __future__ import unicode_literals`](http://python-
future.org/unicode_literals.html) to top of every module doing this). This
step is to ensure your data types are correct internally in your code.
Secondly, make the decision to support Python 3 going forward, with fallbacks
specific for Python 2. This means overriding `str` with `unicode`, and figure
out methods/functions that do not return the same types in both Python
versions should be modified and replaced to return the correct type (being the
Python 3 version). Do note that `bytes` is a reserved word, too, so don't use
that.
Putting this together, your code will look something like this:
import struct
import sys
if sys.version_info < (3, 0):
str = unicode
chr = unichr
def bin_to_float(b):
""" Convert binary string to a float. """
bf = int_to_bytes(int(b, 2), 8) # 8 bytes needed for IEEE 754 binary64
return struct.unpack(b'>d', bf)[0]
def int_to_bytes(n, minlen=0): # helper function
""" Int/long to byte string. """
nbits = n.bit_length() + (1 if n < 0 else 0) # plus one for any sign bit
nbytes = (nbits+7) // 8 # number of whole bytes
ba = bytearray(b'')
for _ in range(nbytes):
ba.append(n & 0xff)
n >>= 8
if minlen > 0 and len(ba) < minlen: # zero pad?
ba.extend((minlen-len(ba)) * b'0')
return u''.join(str(chr(b)) for b in reversed(ba)).encode('latin1') # high bytes at beginning
# tests
def float_to_bin(f):
""" Convert a float into a binary string. """
ba = struct.pack(b'>d', f)
ba = bytearray(ba)
s = u''.join(u'{:08b}'.format(b) for b in ba)
s = s.lstrip(u'0') # strip leading zeros
return (s if s else u'0').encode('latin1') # but leave at least one
for f in 0.0, 1.0, -14.0, 12.546, 3.141593:
binary = float_to_bin(f)
print(u'float_to_bin(%f): %r' % (f, binary))
float = bin_to_float(binary)
print(u'bin_to_float(%r): %f' % (binary, float))
print(u'')
I used the `latin1` codec simply because that's what the byte mappings are
originally defined, and it seems to work
$ python2 foo.py
float_to_bin(0.000000): '0'
bin_to_float('0'): 0.000000
float_to_bin(1.000000): '11111111110000000000000000000000000000000000000000000000000000'
bin_to_float('11111111110000000000000000000000000000000000000000000000000000'): 1.000000
float_to_bin(-14.000000): '1100000000101100000000000000000000000000000000000000000000000000'
bin_to_float('1100000000101100000000000000000000000000000000000000000000000000'): -14.000000
float_to_bin(12.546000): '100000000101001000101111000110101001111110111110011101101100100'
bin_to_float('100000000101001000101111000110101001111110111110011101101100100'): 12.546000
float_to_bin(3.141593): '100000000001001001000011111101110000010110000101011110101111111'
bin_to_float('100000000001001001000011111101110000010110000101011110101111111'): 3.141593
Again, but this time under Python 3.5)
$ python3 foo.py
float_to_bin(0.000000): b'0'
bin_to_float(b'0'): 0.000000
float_to_bin(1.000000): b'11111111110000000000000000000000000000000000000000000000000000'
bin_to_float(b'11111111110000000000000000000000000000000000000000000000000000'): 1.000000
float_to_bin(-14.000000): b'1100000000101100000000000000000000000000000000000000000000000000'
bin_to_float(b'1100000000101100000000000000000000000000000000000000000000000000'): -14.000000
float_to_bin(12.546000): b'100000000101001000101111000110101001111110111110011101101100100'
bin_to_float(b'100000000101001000101111000110101001111110111110011101101100100'): 12.546000
float_to_bin(3.141593): b'100000000001001001000011111101110000010110000101011110101111111'
bin_to_float(b'100000000001001001000011111101110000010110000101011110101111111'): 3.141593
It's a lot more work, but in Python3 you can more clearly see that the types
are done as proper bytes. I also changed your `bytes = []` to a bytearray to
more clearly express what you were trying to do.
|
Confusion with Fancy indexing (for non-fancy people)
Question: Let's assume a multi-dimensional array
import numpy as np
foo = np.random.rand(102,43,35,51)
I know that those last dimensions represent a 2D space (35,51) of which I
would like to index **a range of rows** of a **column** Let's say I want to
have rows 8 to 30 of column 0 From my understanding of indexing I should call
foo[0][0][8::30][0]
Knowing my data though (unlike the random data used here), this is not what I
expected
I could try this that does work but looks ridiculous
foo[0][0][[8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30],0]
Now from what I can find in [this documentation
](https://docs.scipy.org/doc/numpy-
dev/user/quickstart.html#head-864862d3f2bb4c32f04260fac61eb4ef34788c4c) I can
also use something like:
foo[0][0][[8,30],0]
which only gives me the values of rows 8 and 30 while this:
foo[0][0][[8::30],0]
gives an error
File "<ipython-input-568-cc49fe1424d1>", line 1
foo[0][0][[8::30],0]
^
SyntaxError: invalid syntax
I don't understand why the :: argument cannot be passed here. What is then a
way to indicate a range in your indexing syntax?
So I guess my overall question is what would be the proper pythonic equivalent
of this syntax:
foo[0][0][[8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30],0]
Answer: Instead of
foo[0][0][8::30][0]
try
foo[0, 0, 8:30, 0]
The `foo[0][0]` part is the same as `foo[0, 0, :, :]`, selecting a 2d array
(35 x 51). But `foo[0][0][8::30]` selects a subset of those rows
Consider what happens when is use `0::30` on 2d array:
In [490]: np.zeros((35,51))[0::30].shape
Out[490]: (2, 51)
In [491]: np.arange(35)[0::30]
Out[491]: array([ 0, 30])
The `30` is the `step`, not the `stop` value of the slice.
the last `[0]` then picks the first of those rows. The end result is the same
as `foo[0,0,0,:]`.
It is better, in most cases, to index multiple dimensions with the comma
syntax. And if you want the first 30 rows use `0:30`, not `0::30` (that's
basic slicing notation, applicable to lists as well as arrays).
As for:
foo[0][0][[8::30],0]
simplify it to `x[[8::30], 0]`. The Python interpreter accepts `[1:2:3, 0]`,
translating it to `tuple(slice(1,2,3), 0)` and passing it to a `__getitem__`
method. But the colon syntax is accepted in a very specific context. The
interpreter is treating that inner set of brackets as a list, and colons are
not accepted there.
foo[0,0,[1,2,3],0]
is ok, because the inner brackets are a list, and the numpy `getitem` can
handle those.
`numpy` has a tool for converting a slice notation into a list of numbers.
Play with that if it is still confusing:
In [495]: np.r_[8:30]
Out[495]:
array([ 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29])
In [496]: np.r_[8::30]
Out[496]: array([0])
In [497]: np.r_[8:30:2]
Out[497]: array([ 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28])
|
how to print type of keys for a list in python pdb
Question: I'm learning pdb and I can print, or pp a list of objects but how can I print
the type of key for each object? I can see it with pp, it looks like a byte
array but I'd like to know the type. I suppose I could just print debug this
but I'm curious if there's a smarter way to do it when using the debugger.
Answer: Because you wrote
> type of key
I'm assuming that you mean a dictionary. But you _do_ also talk about a "list
of objects", which could also mean
* a list of any kind of object
* a list of dictionaries
But I'll show you two options:
mydict = {b'some bytes': 42,
'a string!': 'fnord',
(1,2,3): 'A tuple! (is that two-pull or tuh-ple?)',
19: 'Just an int',
}
list_of_things = [b'some bytes', 'a string!', (1,2,3), 19, ['a', 'b', 'c']]
import pdb; pdb.set_trace()
Now when `pdb` fires up:
(Pdb) for _ in mydict: print('{} {}'.format(_, type(_)))
19 <type 'int'>
some bytes <type 'str'>
a string! <type 'str'>
(1, 2, 3) <type 'tuple'>
That will give you the keys and types of the keys.
Here's the types and values from the list:
(Pdb) for _ in list_of_things: print('{} {}'.format(_, type(_)))
some bytes <type 'str'>
a string! <type 'str'>
(1, 2, 3) <type 'tuple'>
19 <type 'int'>
['a', 'b', 'c'] <type 'list'>
|
Theano crashing using cuDNN in linux
Question: I am a non-root user on a cluster computer running Scientific Linux release
6.6 (Carbon).
I am experiencing some theano crashes when running code on a GPU with CUDA 7.5
and cuDNN 5. I am using Python 2.7, Theano 0.9, Keras 1.0.7 and Lasange 0.1.
The following crash occurs ONLY when I run the program on a GPU node with
cuDNN enabled. The code completes without issue on a CPU and a GPU with cuDNN
disabled.
Traceback (most recent call last):
File "runner.py", line 306, in <module>
main()
File "runner.py", line 241, in main
queries_exp = __import__(args.exp_model).queries_exp
File "/mnt/nfs2/inf/tjb32/workspace/CNN_EL/nlp-entity-convnet/exp_multi_conv_cosim.py", line 923, in <module>
queries_exp = EntityVectorLinkExp()
File "/mnt/nfs2/inf/tjb32/workspace/CNN_EL/nlp-entity-convnet/exp_multi_conv_cosim.py", line 51, in __init__
self._setup()
File "/mnt/nfs2/inf/tjb32/workspace/CNN_EL/nlp-entity-convnet/exp_multi_conv_cosim.py", line 543, in _setup
on_unused_input='ignore',
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/compile/function.py", line 326, in function
output_keys=output_keys)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/compile/pfunc.py", line 484, in pfunc
output_keys=output_keys)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/compile/function_module.py", line 1788, in orig_function
output_keys=output_keys).create(
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/compile/function_module.py", line 1467, in __init__
optimizer_profile = optimizer(fgraph)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 102, in __call__
return self.optimize(fgraph)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 90, in optimize
ret = self.apply(fgraph, *args, **kwargs)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 235, in apply
sub_prof = optimizer.optimize(fgraph)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 90, in optimize
ret = self.apply(fgraph, *args, **kwargs)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 235, in apply
sub_prof = optimizer.optimize(fgraph)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 90, in optimize
ret = self.apply(fgraph, *args, **kwargs)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 2262, in apply
lopt_change = self.process_node(fgraph, node, lopt)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 1825, in process_node
lopt, node)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 1719, in warn_inplace
return NavigatorOptimizer.warn(exc, nav, repl_pairs, local_opt, node)
File "/home/t/tj/tjb32/.local/lib/python2.7/site-packages/theano/gof/opt.py", line 1705, in warn
raise exc
AssertionError
My .theanorc looks like this:
[global]
floatX = float32
device = gpu
[lib]
cnmem = 1
[nvcc]
fastmath = True
And my profile has the following:
export LD_LIBRARY_PATH=/home/t/tj/tjb32/cuda/lib64:$LD_LIBRARY_PATH
export CPATH=/home/t/tj/tjb32/cuda/include:$CPATH
export LIBRARY_PATH=/home/t/tj/tjb32/cuda/lib64:$LD_LIBRARY_PATH
export PATH=/home/t/tj/tjb32/cuda/bin:$PATH
When I query theano, the following is returned, which suggests to me that
theano is interacting with CUDA and cuDNN.
Using gpu device 0: Tesla K20m (CNMeM is enabled with initial size: 95.0% of memory, cuDNN 5005)
I'm fairly sure that I have installed CUDA and cuDNN correctly, if anyone
could suggest any additional configuration steps that I may have missed that
is causing cuDNN to crash the program, that would be greatly appreciated.
Answer: Not sure if this can be the issues but: export
LIBRARY_PATH=/home/t/tj/tjb32/cuda/lib64:$**LD_** LIBRARY_PATH should be?
export LIBRARY_PATH=/home/t/tj/tjb32/cuda/lib64:$LIBRARY_PATH
|
Porting a python 2 code to Python 3: ICMP Scan with errors
Question:
import random
import socket
import time
import ipaddress
import struct
from threading import Thread
def checksum(source_string):
sum = 0
count_to = (len(source_string) / 2) * 2
count = 0
while count < count_to:
this_val = ord(source_string[count + 1]) * 256 + ord(source_string[count])
sum = sum + this_val
sum = sum & 0xffffffff
count = count + 2
if count_to < len(source_string):
sum = sum + ord(source_string[len(source_string) - 1])
sum = sum & 0xffffffff
sum = (sum >> 16) + (sum & 0xffff)
sum = sum + (sum >> 16)
answer = ~sum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
def create_packet(id):
header = struct.pack('bbHHh', 8, 0, 0, id, 1)
data = 192 * 'Q'
my_checksum = checksum(header + data)
header = struct.pack('bbHHh', 8, 0, socket.htons(my_checksum), id, 1)
return header + data
def ping(addr, timeout=1):
try:
my_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
except Exception as e:
print (e)
packet_id = int((id(timeout) * random.random()) % 65535)
packet = create_packet(packet_id)
my_socket.connect((addr, 80))
my_socket.sendall(packet)
my_socket.close()
def rotate(addr, file_name, wait, responses):
print ("Sending Packets", time.strftime("%X %x %Z"))
for ip in addr:
ping(str(ip))
time.sleep(wait)
print ("All packets sent", time.strftime("%X %x %Z"))
print ("Waiting for all responses")
time.sleep(2)
# Stoping listen
global SIGNAL
SIGNAL = False
ping('127.0.0.1') # Final ping to trigger the false signal in listen
print (len(responses), "hosts found!")
print ("Writing File")
hosts = []
for response in sorted(responses):
ip = struct.unpack('BBBB', response)
ip = str(ip[0]) + "." + str(ip[1]) + "." + str(ip[2]) + "." + str(ip[3])
hosts.append(ip)
file = open(file_name, 'w')
file.write(str(hosts))
print ("Done", time.strftime("%X %x %Z"))
def listen(responses):
global SIGNAL
s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
s.bind(('', 1))
print ("Listening")
while SIGNAL:
packet = s.recv(1024)[:20][-8:-4]
responses.append(packet)
print ("Stop Listening")
s.close()
SIGNAL = True
responses = []
ips = '200.131.0.0/20' # Internet network
wait = 0.002 # Adjust this based in your bandwidth (Faster link is Lower wait)
file_name = 'log1.txt'
ip_network = ipaddress.ip_network(unicode(ips), strict=False)
t_server = Thread(target=listen, args=[responses])
t_server.start()
t_ping = Thread(target=rotate, args=[ip_network, file_name, wait, responses])
t_ping.start()
I tried:
`ip_network = ipaddress.ip_network( ips, strict=False)` instead of `ip_network
= ipaddress.ip_network(unicode(ips), strict=False)`
because of the error: ""NameError: name 'unicode' is not defined"
after:
I got: `my_checksum = checksum(header + data)` -> TypeError: can't concat
bytes to str
so I tried:
`data = bytes(192 * 'Q').encode('utf8')` instead of `data = 192 * 'Q'`
Now, the error is : ""data = bytes (192 * 'Q').encode('utf8') TypeError:
string argument without an encoding"
Could anyone help me to port the code to Python 3 ?
Answer:
import random
import socket
import time
import ipaddress
import struct
from threading import Thread
def checksum(source_string):
sum = 0
count_to = (len(source_string) / 2) * 2
count = 0
while count < count_to:
this_val = source_string[count + 1] * 256 + source_string[count]
sum = sum + this_val
sum = sum & 0xffffffff
count = count + 2
if count_to < len(source_string):
sum = sum + source_string[len(source_string) - 1]
sum = sum & 0xffffffff
sum = (sum >> 16) + (sum & 0xffff)
sum = sum + (sum >> 16)
answer = ~sum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
def create_packet(id):
header = struct.pack('bbHHh', 8, 0, 0, id, 1)
data = 192 * b'Q'
my_checksum = checksum(header + data)
header = struct.pack('bbHHh', 8, 0, socket.htons(my_checksum), id, 1)
return header + data
def ping(addr, timeout=1):
try:
my_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
except Exception as e:
print (e)
packet_id = int((id(timeout) * random.random()) % 65535)
packet = create_packet(packet_id)
my_socket.connect((addr, 80))
my_socket.sendall(packet)
my_socket.close()
def rotate(addr, file_name, wait, responses):
print ("Sending Packets", time.strftime("%X %x %Z"))
for ip in addr:
ping(str(ip))
time.sleep(wait)
print ("All packets sent", time.strftime("%X %x %Z"))
print ("Waiting for all responses")
time.sleep(2)
# Stoping listen
global SIGNAL
SIGNAL = False
ping('127.0.0.1') # Final ping to trigger the false signal in listen
print (len(responses), "hosts found!")
print ("Writing File")
hosts = set()
for response in sorted(responses):
ip = struct.unpack('BBBB', response)
ip = str(ip[0]) + "." + str(ip[1]) + "." + str(ip[2]) + "." + str(ip[3])
hosts.add(ip)
with open(file_name, 'w') as file:
file.write('\n'.join(sorted(hosts, key=lambda item: socket.inet_aton(item))))
print ("Done", time.strftime("%X %x %Z"))
def listen(responses):
global SIGNAL
s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
s.bind(('', 1))
print ("Listening")
while SIGNAL:
packet = s.recv(1024)[:20][-8:-4]
responses.append(packet)
print ("Stop Listening")
s.close()
SIGNAL = True
responses = []
ips = '192.168.1.0/28' # Internet network
wait = 0.002 # Adjust this based in your bandwidth (Faster link is Lower wait)
file_name = 'log1.txt'
ip_network = ipaddress.ip_network(ips, strict=False)
t_server = Thread(target=listen, args=[responses])
t_server.start()
t_ping = Thread(target=rotate, args=[ip_network, file_name, wait, responses])
t_ping.start()
|
How to get "clean" match results in Python
Question: I am a total noob, coding for the first time and trying to learn by doing. I'm
using this:
import re
f = open('aaa.txt', 'r')
string=f.read()
c = re.findall(r"Guest last name: (.*)", string)
print "Dear Mr.", c
that returns
Dear Mr. ['XXXX']
I was wondering, is there any way to get the result like
Dear Mr. XXXX
instead?
Thanks in advance.
Answer: You need to take the first item in the list
print "Dear Mr.", c[0]
|
Is Spark's KMeans unable to handle bigdata?
Question: KMeans has several parameters for its
[training](http://spark.apache.org/docs/latest/api/python/pyspark.mllib.html?highlight=kmeans#pyspark.mllib.clustering.KMeans.train),
with initialization mode is defaulted to kmeans||. The problem is that it
marches quickly (less than 10min) to the first 13 stages, but then **hangs
completely** , without yielding an error!
**Minimal Example** which reproduces the issue (it will succeed if I use 1000
points or random initialization):
from pyspark.context import SparkContext
from pyspark.mllib.clustering import KMeans
from pyspark.mllib.random import RandomRDDs
if __name__ == "__main__":
sc = SparkContext(appName='kmeansMinimalExample')
# same with 10000 points
data = RandomRDDs.uniformVectorRDD(sc, 10000000, 64)
C = KMeans.train(data, 8192, maxIterations=10)
sc.stop()
The job does nothing (it doesn't succeed, fail or progress..), as shown below.
There are no active/failed tasks in the Executors tab. Stdout and Stderr Logs
don't have anything particularly interesting:
[](http://i.stack.imgur.com/aggpL.png)
If I use `k=81`, instead of 8192, it will succeed:
[](http://i.stack.imgur.com/zBKqG.png)
Notice that the two calls of `takeSample()`, [should not be an
issue](http://stackoverflow.com/questions/38986395/sparkkmeans-calls-
takesample-twice), since there were called twice in the random initialization
case.
So, what is happening? Is Spark's Kmeans **unable to scale**? Does anybody
know? Can you reproduce?
* * *
If it was a memory issue, [I would get warnings and errors, as I had been
before](https://gsamaras.wordpress.com/code/memoryoverhead-issue-in-spark/).
Note: placeybordeaux's comments are based on the execution of the job in
_client mode_ , where the driver's configurations are invalidated, causing the
exit code 143 and such (see edit history), not in cluster mode, where there is
_no error reported at all_ , the application _just hangs_.
* * *
From zero323: [Why is Spark Mllib KMeans algorithm extremely
slow?](http://stackoverflow.com/questions/35512139/why-is-spark-mllib-kmeans-
algorithm-extremely-slow) is related, but I think he witnesses some progress,
while mine hangs, I did leave a comment...
[](http://i.stack.imgur.com/osDrR.png)
Answer: I think the 'hanging' is because your executors keep dying. As I mentioned in
a side conversation, this code runs fine for me, locally and on a cluster, in
Pyspark and Scala. However, it takes a lot longer than it should. It is almost
all time spent in k-means|| initialization.
I opened <https://issues.apache.org/jira/browse/SPARK-17389> to track two main
improvements, one of which you can use now. Edit: really, see also
<https://issues.apache.org/jira/browse/SPARK-11560>
First, there are some code optimizations that would speed up the init by about
13%.
However most of the issue is that it default to 5 steps of k-means|| init,
when it seems that 2 is almost always just as good. You can set initialization
steps to 2 to see a speedup, especially in the stage that's hanging now.
In my (smaller) test on my laptop, init time went from 5:54 to 1:41 with both
changes, mostly due to setting init steps.
|
Alembic not handling column_types.PasswordType : Flask+SQLAlchemy+Alembic
Question: **Background**
I'm trying to use a PostgreSQL back-end instead of Sqlite in this [Flask +
RESTplus server example](https://github.com/frol/flask-restplus-server-
example).
I faced an issue with the PasswordType db column type. In order to make it
work, I had to change the following code in
[app/modules/users/models.py](https://github.com/frol/flask-restplus-server-
example/blob/master/app/modules/users/models.py#L46)
password = db.Column(
column_types.PasswordType(
max_length=128,
schemes=('bcrypt', )
),
nullable=False
)
to
password = db.Column(db.String(length=128), nullable=False)
which is really bad as passwords will be stored in clear text... and I need
your help!
After changing the [line 13 to 15 in
tasks/app/db_templates/flask/script.py.mako ](https://github.com/frol/flask-
restplus-server-
example/blob/master/tasks/app/db_templates/flask/script.py.mako#L13-15) to
from alembic import op
import sqlalchemy as sa
import sqlalchemy_utils
${imports if imports else ""}
I get the following error message, apparently related to passlib:
2016-08-31 23:18:52,751 [INFO] [alembic.runtime.migration] Context impl PostgresqlImpl.
2016-08-31 23:18:52,752 [INFO] [alembic.runtime.migration] Will assume transactional DDL.
2016-08-31 23:18:52,759 [INFO] [alembic.runtime.migration] Running upgrade -> 99b329343a41, empty message
Traceback (most recent call last):
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/type_api.py", line 359, in dialect_impl
return dialect._type_memos[self]['impl']
File "/usr/local/lib/python3.5/weakref.py", line 365, in __getitem__
return self.data[ref(key)]
KeyError: <weakref at 0x7fde70d524a8; to 'PasswordType' at 0x7fde70a840b8>
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/bin/invoke", line 11, in <module>
sys.exit(program.run())
File "/usr/local/lib/python3.5/site-packages/invoke/program.py", line 270, in run
self.execute()
File "/usr/local/lib/python3.5/site-packages/invoke/program.py", line 381, in execute
executor.execute(*self.tasks)
File "/usr/local/lib/python3.5/site-packages/invoke/executor.py", line 113, in execute
result = call.task(*args, **call.kwargs)
File "/usr/local/lib/python3.5/site-packages/invoke/tasks.py", line 111, in __call__
result = self.body(*args, **kwargs)
File "/usr/src/app/tasks/app/run.py", line 35, in run
context.invoke_execute(context, 'app.db.upgrade')
File "/usr/src/app/tasks/__init__.py", line 72, in invoke_execute
results = Executor(namespace, config=context.config).execute((command_name, kwargs))
File "/usr/local/lib/python3.5/site-packages/invoke/executor.py", line 113, in execute
result = call.task(*args, **call.kwargs)
File "/usr/local/lib/python3.5/site-packages/invoke/tasks.py", line 111, in __call__
result = self.body(*args, **kwargs)
File "/usr/src/app/tasks/app/db.py", line 177, in upgrade
command.upgrade(config, revision, sql=sql, tag=tag)
File "/usr/local/lib/python3.5/site-packages/alembic/command.py", line 174, in upgrade
script.run_env()
File "/usr/local/lib/python3.5/site-packages/alembic/script/base.py", line 407, in run_env
util.load_python_file(self.dir, 'env.py')
File "/usr/local/lib/python3.5/site-packages/alembic/util/pyfiles.py", line 93, in load_python_file
module = load_module_py(module_id, path)
File "/usr/local/lib/python3.5/site-packages/alembic/util/compat.py", line 68, in load_module_py
module_id, path).load_module(module_id)
File "<frozen importlib._bootstrap_external>", line 385, in _check_name_wrapper
File "<frozen importlib._bootstrap_external>", line 806, in load_module
File "<frozen importlib._bootstrap_external>", line 665, in load_module
File "<frozen importlib._bootstrap>", line 268, in _load_module_shim
File "<frozen importlib._bootstrap>", line 693, in _load
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 662, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "migrations/env.py", line 93, in <module>
run_migrations_online()
File "migrations/env.py", line 86, in run_migrations_online
context.run_migrations()
File "<string>", line 8, in run_migrations
File "/usr/local/lib/python3.5/site-packages/alembic/runtime/environment.py", line 797, in run_migrations
self.get_context().run_migrations(**kw)
File "/usr/local/lib/python3.5/site-packages/alembic/runtime/migration.py", line 312, in run_migrations
step.migration_fn(**kw)
File "/usr/src/app/migrations/versions/99b329343a41_.py", line 47, in upgrade
sa.UniqueConstraint('username')
File "<string>", line 8, in create_table
File "<string>", line 3, in create_table
File "/usr/local/lib/python3.5/site-packages/alembic/operations/ops.py", line 1098, in create_table
return operations.invoke(op)
File "/usr/local/lib/python3.5/site-packages/alembic/operations/base.py", line 318, in invoke
return fn(self, operation)
File "/usr/local/lib/python3.5/site-packages/alembic/operations/toimpl.py", line 101, in create_table
operations.impl.create_table(table)
File "/usr/local/lib/python3.5/site-packages/alembic/ddl/impl.py", line 194, in create_table
self._exec(schema.CreateTable(table))
File "/usr/local/lib/python3.5/site-packages/alembic/ddl/impl.py", line 118, in _exec
return conn.execute(construct, *multiparams, **params)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/engine/base.py", line 914, in execute
return meth(self, multiparams, params)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/ddl.py", line 68, in _execute_on_connection
return connection._execute_ddl(self, multiparams, params)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/engine/base.py", line 962, in _execute_ddl
compiled = ddl.compile(dialect=dialect)
File "<string>", line 1, in <lambda>
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/elements.py", line 494, in compile
return self._compiler(dialect, bind=bind, **kw)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/ddl.py", line 26, in _compiler
return dialect.ddl_compiler(dialect, self, **kw)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/compiler.py", line 190, in __init__
self.string = self.process(self.statement, **compile_kwargs)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/compiler.py", line 213, in process
return obj._compiler_dispatch(self, **kwargs)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/visitors.py", line 81, in _compiler_dispatch
return meth(self, **kw)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/compiler.py", line 2157, in visit_create_table
and not first_pk)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/compiler.py", line 213, in process
return obj._compiler_dispatch(self, **kwargs)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/visitors.py", line 81, in _compiler_dispatch
return meth(self, **kw)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/compiler.py", line 2188, in visit_create_column
first_pk=first_pk
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/dialects/postgresql/base.py", line 1580, in get_column_specification
impl_type = column.type.dialect_impl(self.dialect)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/type_api.py", line 361, in dialect_impl
return self._dialect_info(dialect)['impl']
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/type_api.py", line 403, in _dialect_info
impl = self._gen_dialect_impl(dialect)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy/sql/type_api.py", line 763, in _gen_dialect_impl
typedesc = self.load_dialect_impl(dialect).dialect_impl(dialect)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy_utils/types/password.py", line 194, in load_dialect_impl
impl = postgresql.BYTEA(self.length)
File "/usr/local/lib/python3.5/site-packages/sqlalchemy_utils/types/password.py", line 168, in length
self._max_length = self.calculate_max_length()
File "/usr/local/lib/python3.5/site-packages/sqlalchemy_utils/types/password.py", line 176, in calculate_max_length
for name in self.context.schemes():
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 2714, in __getattribute__
self._lazy_init()
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 2708, in _lazy_init
super(LazyCryptContext, self).__init__(**kwds)
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 1707, in __init__
self.load(kwds)
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 1896, in load
config = _CryptConfig(source)
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 1019, in __init__
self._init_options(source)
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 1097, in _init_options
key, value = norm_context_option(key, value)
File "/usr/local/lib/python3.5/site-packages/passlib/context.py", line 1162, in _norm_context_option
raise KeyError("unknown CryptContext keyword: %r" % (key,))
KeyError: "unknown CryptContext keyword: 'length'"
Any idea? Thanks in advance for your help!
Answer: I see that you are having a new migration `99b329343a41_.py` (it doesn't exist
in my Flask-RESTplus-example-server). Please, review your new migration and
**remove** everything related to PasswordType. It is a bug in SQLAlchemy-
Utils, which doesn't play nice with Alembic:
<https://github.com/kvesteri/sqlalchemy-utils/issues/106>
|
Unable to run a basic GraphFrames example
Question: Trying to run a simple GraphFrame example using pyspark.
spark version : 2.0
graphframe version : 0.2.0
I am able to import graphframes in Jupyter:
from graphframes import GraphFrame
GraphFrame
graphframes.graphframe.GraphFrame
I get this error when I try and create a GraphFrame object:
---------------------------------------------------------------------------
Py4JJavaError Traceback (most recent call last)
<ipython-input-23-2bf19c66804d> in <module>()
----> 1 gr_links = GraphFrame(df_web_page, df_parent_child_link)
/Users/roopal/software/graphframes-release-0.2.0/python/graphframes/graphframe.pyc in __init__(self, v, e)
60 self._sc = self._sqlContext._sc
61 self._sc._jvm.org.apache.spark.ml.feature.Tokenizer()
---> 62 self._jvm_gf_api = _java_api(self._sc)
63 self._jvm_graph = self._jvm_gf_api.createGraph(v._jdf, e._jdf)
64
/Users/roopal/software/graphframes-release-0.2.0/python/graphframes/graphframe.pyc in _java_api(jsc)
32 def _java_api(jsc):
33 javaClassName = "org.graphframes.GraphFramePythonAPI"
---> 34 return jsc._jvm.Thread.currentThread().getContextClassLoader().loadClass(javaClassName) \
35 .newInstance()
36
/Users/roopal/software/spark-2.0.0-bin-hadoop2.7/python/lib/py4j-0.10.1-src.zip/py4j/java_gateway.py in __call__(self, *args)
931 answer = self.gateway_client.send_command(command)
932 return_value = get_return_value(
--> 933 answer, self.gateway_client, self.target_id, self.name)
934
935 for temp_arg in temp_args:
/Users/roopal/software/spark-2.0.0-bin-hadoop2.7/python/pyspark/sql/utils.pyc in deco(*a, **kw)
61 def deco(*a, **kw):
62 try:
---> 63 return f(*a, **kw)
64 except py4j.protocol.Py4JJavaError as e:
65 s = e.java_exception.toString()
/Users/roopal/software/spark-2.0.0-bin-hadoop2.7/python/lib/py4j-0.10.1-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
310 raise Py4JJavaError(
311 "An error occurred while calling {0}{1}{2}.\n".
--> 312 format(target_id, ".", name), value)
313 else:
314 raise Py4JError(
Py4JJavaError: An error occurred while calling o138.loadClass.
: java.lang.ClassNotFoundException: org.graphframes.GraphFramePythonAPI
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:237)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:280)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:128)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:211)
at java.lang.Thread.run(Thread.java:745)
The python code tries to read the java class (in the jar) I guess, but cant
seem to find it. Any suggestions how to fix this?
Answer: Make sure that your PYSPARK_SUBMIT_ARGS is updated to have "--packages
graphframes:graphframes:0.2.0-spark2.0" in your kernel.json
~/.ipython/kernels//kernel.json.
You probably already looked at the following
[link](https://developer.ibm.com/clouddataservices/2016/07/15/intro-to-apache-
spark-graphframes/). It has more details on Jupiter setup. Basically, pyspark
has to be supplied the graphframes.jar.
|
Is my adaptation of point-in-polygon (jordan curve theorem) in python correct?
Question: **Problem**
I recently found a need to determine if my points are inside of a polygon. So
I learned about [this](https://sidvind.com/wiki/Point-in-
polygon:_Jordan_Curve_Theorem) approach in C++ and adapted it to python.
However, the C++ code I was studying isn't quite right I think? I believe I
have fixed it, but I am not quite sure so I was hoping folks brighter than me
might help me caste some light on this?
The theorem is super simple and the idea is like this, given an nth closed
polygon you draw an arbitrary line, if your point is inside, you line will
intersect with the edges an odd number of times. Otherwise, you will be even
and it is outside the polygon. Pretty freaking cool.
I had the following test cases:
polygon_x = [5, 5, 11, 10]
polygon_y = [5, 10, 5, 10]
test1_x = 6
test1_y = 6
result1 = point_in_polygon(test1_x, test1_y, polygon_x, polygon_y)
print(result1)
test2_x = 13
test2_y = 5
result2 = point_in_polygon(test2_x, test2_y, polygon_x, polygon_y)
print(result2)
The above would give me both false if I defined it as follows:
if polygon_x[i] < polygon_x[(i+1) % length]:
temp_x = polygon_x[i]
temp_y = polygon_x[(i+1) % length]
else:
temp_x = polygon_x[(i+1) % length]
temp_y = polygon_x[i]
This is wrong! I should be getting `true` for `result1` and then `false` for
`result2`. So clearly, something is funky.
The code I was reading in C++ makes sense except for the above. In addition,
it failed my test case which made me think that `temp_y` should be defined
with `polygon_y` and not `polygon_x`. Sure enough, when I did this, my test
case for `(6,6)` passes. It still fails when my points are on the line, but as
long as I am inside the polygon, it will pass. Expected behavior.
## Polygon code adopted to python
def point_in_polygon(self, target_x, target_y, polygon_x, polygon_y):
print(polygon_x)
print(polygon_y)
#Variable to track how many times ray crosses a line segment
crossings = 0
temp_x = 0
temp_y = 0
length = len(polygon_x)
for i in range(0,length):
if polygon_x[i] < polygon_x[(i+1) % length]:
temp_x = polygon_x[i]
temp_y = polygon_y[(i+1) % length]
else:
temp_x = polygon_x[(i+1) % length]
temp_y = polygon_y[i]
print(str(temp_x) + ", " + str(temp_y))
#check
if target_x > temp_x and target_x <= temp_y and (target_y < polygon_y[i] or target_y <= polygon_y[(i+1)%length]):
eps = 0.000001
dx = polygon_x[(i+1) % length] - polygon_x[i]
dy = polygon_y[(i+1) % length] - polygon_y[i]
k = 0
if abs(dx) < eps:
k = 999999999999999999999999999
else:
k = dy/dx
m = polygon_y[i] - k * polygon_x[i]
y2 = k*target_x + m
if target_y <= y2:
crossings += 1
print(crossings)
if crossings % 2 == 1:
return True
else:
return False
**Summary**
Can someone please explain to me what the `temp_x` and `temp_y` approaches are
doing? Also, if my fix for redefining the `temp_x` for `polygon_x` and
`temp_y` for `polygon_y` is the correct approach? I doubt it. Here is why.
What is going on for `temp_x` and `temp_y` doesn't quite make sense to me. For
`i = 0`, clearly `polygon_x[0] < polygon_x[1]` is `false`, so we get
`temp_x[1] = 5` and `temp_y[0] = 5`. That is `(5,5)`. This just happens to be
one of my pairs. However, suppose I feed the algorithm my points out of order
(by axis, pairwise integrity is always a must), something like:
x = [5, 10, 10, 5]
y = [10,10, 5, 5]
In this case, when `i = 0`, we get `temp_x[1] = 10` and `temp_y[0] = 10`.
Okay, by coincidence `(10,10)`. I also tested points against the "corrected"
algorithm `(9,9)` and it is still inside. In short, I am trying to find a
counterexample, for why my fix won't work, but I can't. If this is working, I
need to understand what the method is doing and hope someone could help
explain it to me?
Regardless, if I am right or wrong, I would appreciate it if someone could
help shed some better light on this problem. I'm even open to solving the
problem in a more efficient way for n-polygons, but I want to make sure I am
understanding code correctly. As a coder, I am uncomfortable with a method
that doesn't quite make sense.
Thank you so much for listening to my thoughts above. Any suggestions greatly
welcomed.
Answer: You've misunderstood what the `x1` and `x2` values in the linked C++ code are
for, and that misunderstanding has caused you to pick inappropriate variable
names in Python. Both of the variables contain `x` values, so `temp_y` is a
very misleading name. Better names might be `min_x` and `max_x`, since they
are the minimum and maximum of the `x` values of the vertices that make up the
polygon edge. A clearer version of the code might be written as:
for i in range(length):
min_x = min(polygon_x[i], polygon_x[(i+1)%length])
max_x = max(polygon_x[i], polygon_x[(i+1)%length])
if x_min < target_x <= x_max:
# ...
This is perhaps a little less efficient than the C++ style of code, since
calling both `min` and `max` will compare the values twice.
Your comment about the order of the points suggests that there's a further
misunderstanding going on, which might explain the unexpected results you were
seeing when setting `temp_y` to a value from `polygon_x`. The order of the
coordinates in the polygon lists is important, as the edges go from one
coordinate pair to the next around the list (with the last pair of coordinates
connecting to the first pair to close the polygon). If you reorder them, the
edges of the polygon will get switched around.
The example coordinates you give in your code (`polygon_x = [5, 5, 11, 10]`
and `polygon_y = [5, 10, 5, 10]`) don't describe a normal kind of polygon.
Rather, you get a (slightly lopsided) bow-tie shape, with two diagonal edges
crossing each other like an `X` in the middle. That's not actually a problem
for this algorithm though.
However, the first point you're testing lies exactly on one of those diagonal
edges (the one that wraps around the list, from the last vertex, `(10, 10)` to
the first, `(5, 5)`). Whether the code will decide it's inside or outside of
the polygon likely comes down to floating point rounding and the choice of
operator between `<` or `<=`. Either answer could be considered "correct" in
this situation.
When you reordered the coordinates later in the question (and incidentally
change an `11` to a `10`), you turned the bow-tie into a square. Now the `(6,
6)` test is fully inside the shape, and so the code will work if you don't
assign a `y` coordinate to the second `temp` variable.
|
Python 2.7 TypeError: 'NoneType' object has no attribute '_getitem_'
Question: I'm pretty new to coding and have been trying some things out. I am getting
this error when I run a python script I have. I have read that this error is
because something is returning "None" but I'm having trouble figuring out what
is causing it (still trying to learn all of this).
The purpose of the script is pulling thumbnails from videos and searching the
internet for other instances of the same thing. After running my python
script, it returns a result of:
[*] Retrieving video ID: VIDEOID
Traceback (most recent call last):
File "VidSearch.py", line 40, in <module>
thumbnails = video_data['items'][0]['snippet']['thumbnails']
TypeError: 'NoneType' object has no atribute '_getitem_'
The following is the script I am running (Youtube Key removed):
import argparse
import requests
import json
from pytineye import TinEyeAPIRequest
tineye = TinEyeAPIRequest('http://api.tineye.com/rest/','PUBLICKEY','PRIVATEKEY')
youtube_key = "VIDEOID"
ap = argparse.ArgumentParser()
ap.add_argument("-v","--videoID", required=True,help="The videoID of the YouTube video. For example: https://www.youtube.com/watch?v=VIDEOID")
args = vars(ap.parse_args())
video_id = args['videoID']
#
# Retrieve the video details based on videoID
#
def youtube_video_details(video_id):
api_url = "https://www.googleapis.com/youtube/v3/videos?part=snippet%2CrecordingDetails&"
api_url += "id=%s&" % video_id
api_url += "key=%s" % youtube_key
response = requests.get(api_url)
if response.status_code == 200:
results = json.loads(response.content)
return results
return None
print "[*] Retrieving video ID: %s" % video_id
video_data = youtube_video_details(video_id)
thumbnails = video_data['items'][0]['snippet']['thumbnails']
print "[*] Thumbnails retrieved. Now submitting to TinEye."
url_list = []
# add the thumbnails from the API to the list
for thumbnail in thumbnails:
url_list.append(thumbnails[thumbnail]['url'])
# build the manual URLS
for count in range(4):
url = "http://img.youtube.com/vi/%s/%d.jpg" % (video_id,count)
url_list.append(url)
results = []
# now walk over the list of URLs and search TinEye
for url in url_list:
print "[*] Searching TinEye for: %s" % url
try:
result = tineye.search_url(url)
except:
pass
if result.total_results:
results.extend(result.matches)
result_urls = []
dates = {}
for match in results:
for link in match.backlinks:
if link.url not in result_urls:
result_urls.append(link.url)
dates[link.crawl_date] = link.url
print
print "[*] Discovered %d unique URLs with image matches." % len(result_urls)
for url in result_urls:
print url
oldest_date = sorted(dates.keys())
print
print "[*] Oldest match was crawled on %s at %s" % (str(oldest_date[0]),dates[oldest_date[0]])
I know it's probably something simple but I can't seem to figure it out for
the life of me. Any help would be greatly appreciated.
Answer: In your `youtube_video_details` method. the response.status_code maybe is not
`200`, so the method return the `None`
So you can do like this:
video_data = youtubo_video_details(video_id)
if not video_data:
thumbnails = video_data['items'][0]['snippet']['thumbnails']
|
How to convert tar.gz file to zip using Python only?
Question: Does anybody has any code for converting tar.gz file into zip using only
Python code? I have been facing many issues with tar.gz as mentioned in the
[How can I read tar.gz file using pandas read_csv with gzip compression
option?](http://stackoverflow.com/questions/39263929/how-can-i-read-tar-gz-
file-using-pandas-read-csv-with-gzip-compression-option)
Answer: You would have to use the
[tarfile](https://docs.python.org/3/library/tarfile.html) module, with mode
`'r|gz'` for reading. Then use
[zipfile](https://docs.python.org/3/library/zipfile.html#module-zipfile) for
writing.
import tarfile, zipfile
tarf = tarfile.open( name='mytar.tar.gz', mode='r|gz' )
zipf = ZipFile.open( name='myzip.zip', mode='a', compress_type=ZIP_DEFLATED )
for m in tarf.getmembers():
f = tarf.extractfile( m )
fl = f.read()
fn = m.name
zipf.writestr( fn, fl )
# or zipf.writestr( fn, f ) ?
tarf.close()
zipf.close()
You can use `is_tarfile()` to check for a valid tar file.
Perhaps you could also use
[`shutil`](https://docs.python.org/3/library/shutil.html#archiving-
operations), but I think it cannot work on memory.
PS: I do not have python in this PC, so there may be a few things to tune.
|
Error on Data Pickle in Python
Question: I need to save my Training Data set in Data Pickle. Here is the code. When
execute this code there was an error. How do I fix this error. I need to save
featureCounts and labelCounts variables in two pickles.
from __future__ import division
import collections
import math
import pickle
class TrainClassifier:
def __init__(self, arffFile):
self.trainingFile = arffFile
self.features = {}
self.featureNameList = []
self.featureCounts = collections.defaultdict(lambda: 1)
self.featureVectors = []
self.labelCounts = collections.defaultdict(lambda: 0)
def DataTraning(self):
for fv in self.featureVectors:
self.labelCounts[fv[len(fv)-1]] += 1 #udpate count of the label
for counter in range(0, len(fv)-1):
self.featureCounts[(fv[len(fv)-1], self.featureNameList[counter], fv[counter])] += 1
for label in self.labelCounts:
for feature in self.featureNameList[:len(self.featureNameList)-1]:
self.labelCounts[label] += len(self.features[feature])
def GetValues(self):
file = open(self.trainingFile, 'r')
for line in file:
if line[0] != '@': #start of actual data
self.featureVectors.append(line.strip().lower().split(','))
else: #feature definitions
if line.strip().lower().find('@data') == -1 and (not line.lower().startswith('@relation')):
self.featureNameList.append(line.strip().split()[1])
self.features[self.featureNameList[len(self.featureNameList) - 1]] = line[line.find('{')+1: line.find('}')].strip().split(',')
file.close()
def SaveOnPickle(self):
f = open('dict.pickle', 'wb')
pickle.dump(self.labelCounts, f)
f.close()
if __name__ == "__main__":
Predic = TrainClassifier("Military.arff")
Predic.GetValues()
Predic.DataTraning()
Predic.SaveOnPickle()
Here is the Error
Traceback (most recent call last):
File "C:\wamp64\www\M360\M360py\src\TrainClassifier.py", line 69, in <module>
Predic.SaveOnPickle()
File "C:\wamp64\www\M360\M360py\src\TrainClassifier.py", line 43, in SaveOnPickle
pickle.dump(self.labelCounts, f)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 1370, in dump
Pickler(file, protocol).dump(obj)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 224, in dump
self.save(obj)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 331, in save
self.save_reduce(obj=obj, *rv)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 401, in save_reduce
save(args)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 286, in save
f(self, obj) # Call unbound method with explicit self
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 562, in save_tuple
save(element)
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 286, in save
f(self, obj) # Call unbound method with explicit self
File "C:\Users\Udara\AppData\Roaming\NetBeans\8.1\jython-2.7.0\Lib\pickle.py", line 746, in save_global
raise PicklingError(
pickle.PicklingError: Can't pickle <function <lambda> at 0x5>: it's not found as __main__.<lambda>
Answer: you cannot serialize `self.labelCounts` because it is a defaultdict (no
problem with that) with a `lambda` in it: here's the catch: Pickle cannot
serialize functions.
you wrote:
self.labelCounts = collections.defaultdict(lambda: 0)
But you are lucky: you don't need a lambda here (you need a lambda for mutable
objects such as lists but with 0 no problem), just do:
self.labelCounts = collections.defaultdict(0)
(of course it's the same problem and solution for your other dict
`featureCounts`). Do that:
self.featureCounts = collections.defaultdict(1)
|
Camera calibration with circular pattern
Question: I'm following [this tutorial](http://opencv-python-
tutroals.readthedocs.io/en/latest/py_tutorials/py_calib3d/py_calibration/py_calibration.html#calibration)
to calibrate my camera (with some lens) on Raspberry Pi, but using a [circular
pattern](http://nerian.com/support/resources/patterns/) instead of the
chessboard one. The problem is that the resulting undistorted image is
shrinked and not full, and when I get every shrinking away from the code, it
looks like the right part of
[](http://i.stack.imgur.com/L9sgp.jpg)
(usually it's even worse). The question is if it is possible to do something
with the code so that it would give away a picture like [the example from the
tutorial](http://opencv-python-
tutroals.readthedocs.io/en/latest/_images/calib_result.jpg). Do I have to use
the chessboard pattern for this?
My code:
import numpy as np
import cv2
from picamera.array import PiRGBArray
from picamera import PiCamera
import time
# termination criteria
criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
# prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
#objp = np.zeros((4*11,3), np.float32)
#objp[:,:2] = np.mgrid[0:7,0:6].T.reshape(-1,2)
objp=np.array([[0,0,0],[1,0,0],[2,0,0],[3,0,0],[0.5,0.5,0],[1.5,0.5,0],[2.5,0.5,0],[3.5,0.5,0]])
for y in range(2,11):
for x in range(4):
objp=np.append(objp,[np.array([objp[4*(y-2)+x][0],objp[4*(y-2)+x][1]+1,0])],axis=0)
# Arrays to store object points and image points from all the images.
objpoints = [] # 3d point in real world space
imgpoints = [] # 2d points in image plane.
#images = glob.glob('pict*.jpg')
# initialize the camera and grab a reference to the raw camera capture
camera = PiCamera()
camera.resolution = (640, 480)
camera.framerate = 32
rawCapture = PiRGBArray(camera, size=(640, 480))
# allow the camera to warmup
time.sleep(0.1)
ret0=[]
j=0
for i,frame in enumerate(camera.capture_continuous(rawCapture, format="bgr", use_video_port=True)):
image = frame.array
img=image[::-1]
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
# Find the chess board corners
ret, corners = cv2.findCirclesGrid(gray, (4,11),None,flags=cv2.CALIB_CB_ASYMMETRIC_GRID)
# If found, add object points, image points (after refining them)
if ret == True and np.sum(np.int32(ret0))<15 and not i%10:
ret0.append(ret)
print("{} more for proper calibration".format(15-np.sum(np.int32(ret0))))
objpoints.append(objp.astype('float32'))
corners2 = cv2.cornerSubPix(gray,corners,(11,11),(-1,-1),criteria)
imgpoints.append(corners2.reshape(-1, 2).astype('float32'))
# Draw and display the corners
img = cv2.drawChessboardCorners(img.copy(), (4,11), corners2,ret)
cv2.imshow('img',img)
cv2.waitKey(1000)
cv2.imwrite('cal{}.jpg'.format(j),img)
j+=1
rawCapture.truncate(0)
elif np.sum(np.int32(ret0))<15:
cv2.imshow('img',img)
cv2.waitKey(1)
rawCapture.truncate(0)
else:
rawCapture.truncate(0)
break
dist = np.array([-0.13615181, 0.53005398, 0, 0, 0]) # no translation
ret, mtx, dist, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints, gray.shape[::-1],None,None)
h, w = img.shape[:2]
newcameramtx, roi=cv2.getOptimalNewCameraMatrix(mtx,dist,(w,h),1,(w,h))
np.savetxt('newcameramtx.out',newcameramtx)
np.savetxt('mtx.out',mtx)
np.savetxt('dist.out',dist)
#img=cv2.imread('pict1.jpg')
# undistort
dst = cv2.undistort(img, mtx, dist, None, newcameramtx)
# crop the image
x,y,w,h = roi
dst = dst[y:y+h, x:x+w]
cv2.imwrite('calibresult.png',dst)
cv2.imshow('undistorted',dst)
cv2.waitKey(0)&0xFF
cv2.destroyAllWindows()
UPD: I've tried calibration with the chessboard pattern, and the program
didn't even want to recognize the pattern! Here are examples with detected
circular pattern:
[](http://i.stack.imgur.com/BMxcg.jpg)
[](http://i.stack.imgur.com/x2L9b.jpg)
[](http://i.stack.imgur.com/tA3Mf.jpg)
[](http://i.stack.imgur.com/Sdm0A.jpg)
So the program allegedly detects the circles, but not as ideally, as it would
be wanted.
Answer: You could try to tune the parameters of the blob detector. By the default the
`findCirclesGrid` uses the SimpleBlobDetector. So try to adust the parameters,
for example:
params = cv2.SimpleBlobDetector_Params()
params.minArea = 10;
params.minDistBetweenBlobs = 5;
detector = cv2.SimpleBlobDetector_create(params)
and then pass it to findCirclesGrid:
cv2.findCirclesGrid(gray, (4,11),None,flags=cv2.CALIB_CB_ASYMMETRIC_GRID,detector)
Additionaly you can try to use `cv2.CALIB_CB_ASYMMETRIC_GRID +
cv2.CALIB_CB_CLUSTERING`
For more information about the SimpleBlobDetector and its parameters see [this
tutrial](https://www.learnopencv.com/blob-detection-using-opencv-python-c/).
|
Python / Pygame FULLSCREEN Tag Creates A Game Screen That Is To Large For The Screen
Question: **UPDATED ISSUE**
I have discovered the issue appears to be with the fact that I am using the
FULLSCREEN tag to create the window. I added a rectangle to be drawn in the
top left of the scree (0, 0), but when I run the program, It is mostly off the
screen. Then, when I Alt-Tab away and back, the rectangle is appropriately
placed at 0,0 and the turret is off center.
So basically, when the program starts, the game screen is larger than my
actual screen, but centered. Then after Alt-Tab, the game screen is lined up
with 0,0 but since the game screen is larger than my screen, the turret looks
off center, but is actually centered relative to the game.
So the real question is why does using the FULLSCREEN tag make a screen larger
than my computer screen?
**ORIGINAL ISSUE**
I am building a simple demonstration of a turret in the center of the screen
which follows the location of the cursor as if to fire where it is. Everything
works perfectly until I Alt-Tab away from the screen, and then Alt-Tab back.
At this point to turret is now off center (down and to the right)
import pygame, math
pygame.init()
image_library = {}
screen_dimen = pygame.display.Info()
print("Screen Dimensions ", screen_dimen)
def get_image(name):
if name not in image_library:
image = pygame.image.load(name)
image_library[name] = image
else:
image = image_library[name]
return image
robot_turret_image = get_image('robot_turret.png')
screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
done = False
clock = pygame.time.Clock()
while not done:
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
if event.type == pygame.MOUSEMOTION:
print(event.pos)
if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
done = True
screen.fill((0, 0, 0))
pos = pygame.mouse.get_pos()
angle = 360 - math.atan2(pos[1] - (screen_dimen.current_h / 2),
pos[0] - (screen_dimen.current_w / 2)) * 180 / math.pi
rot_image = pygame.transform.rotate(robot_turret_image, angle)
rect = rot_image.get_rect(center=(screen_dimen.current_w / 2, screen_dimen.current_h / 2))
screen.blit(rot_image, rect)
color = (0, 128, 255)
pygame.draw.rect(screen, color, pygame.Rect(0, 0, 200, 200))
pygame.display.update()
clock.tick(60)
It seems that the center is now off. I have printed out the screen dimensions
before and after the Alt-Tab and they are the same, so I can't figure out why
the image moves. I believe I am missing something regarding state changes with
Pygame, but can't figure out what. If it is relevant, I am on Windows 10.
Answer: Alright, I discovered a solution from
[gamedev.stackexchange](http://gamedev.stackexchange.com/questions/105750/pygame-
fullsreen-display-issue)
And I will re-hash it here. The issue was that Using the fullscreen tag was
making a screen larger than my computer screen. The following code solves this
import ctypes
ctypes.windll.user32.SetProcessDPIAware()
true_res = (ctypes.windll.user32.GetSystemMetrics(0), ctypes.windll.user32.GetSystemMetrics(1))
pygame.display.set_mode(true_res,pygame.FULLSCREEN)
It is important to note that this is potentially just a windows fix, but I do
not have another system with which to test it on. But It works on Windows 10
with python 3.5.1 and pygame 1.9.2a0
|
Python Check for decimals
Question: i'm making a program which divides a lot of numbers and I want to check if the
number gets decimals or not. I also want it to print those decimals. Example:
foo = 7/3
if foo has a 3 in the decimals: (Just an example of what I want to do there)
print("It works!)
elif foo has no decimals: (another example)
print("it has no decimals")
EDIT: Ok, so since "check which decimal is afterwards" brought some confusion,
let me explain. I want to be able to check IF a number has decimals. For
example, 7/3 (foo) gives me decimals, but I want python to tell me that
without me having to do the math. forget the "which decimal" part
Answer: If you just want to test whether a division has decimals, just check the
modulo:
foo = a % b
if foo != 0:
# Then foo contains decimals
pass
if foo == 0:
# Then foo does NOT contain decimals
pass
However (since your question is a bit unclear) if you want to split the
integer and decimal parts then use
[`math.modf()`](https://docs.python.org/2/library/math.html#math.modf)
function:
import math
x = 1234.5678
math.modf(x) # (0.5678000000000338, 1234.0)
|
Issue deploying Django project to Apache via WSGI
Question: Ubuntu 14.04.4 and Django 1.10
I'm trying to deploy a simple Django app that works perfectly in development
to Apache, via WSGI. The relevant bits in my Apache config file:
<VirtualHost [my IP]>
WSGIScriptAlias /Django/MedFormUpdates /home/web/inside/django/MedFormUpdates/MedFormUpdates/wsgi.py
WSGIApplicationGroup %{GLOBAL}
</VirtualHost>
WSGIPythonPath /home/web/inside/django/MedFormUpdates/MedFormUpdates
<Directory "/home/web/inside/django/MedFormUpdates/MedFormUpdates">
Options ExecCGI
<Files wsgi.py>
Require all granted
</Files>
</Directory>
In my wsgi.py file:
import os, sys
from django.core.wsgi import get_wsgi_application
sys.path.append('/home/web/inside/django')
sys.path.append('/home/web/inside/django/MedFormUpdates')
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "MedFormUpdates.settings")
application = get_wsgi_application()
And in my settings.py:
WSGI_APPLICATION = 'MedFormUpdates.wsgi.application'
When I attempt loading the page, I get "**We're sorry, the web server had an
internal error.** " - with the Apache log showing
End of script output before headers: wsgi.py
I've been through every Django/WSGI/Apache thread that I can find, and this is
driving me nuts. Any insight is appreciated. Thanks.
Answer: It turns out that we have another Apache configuration file in the directory
/etc/apache2/conf-enabled which has the following setting, which binds Python
scripts (as well as Perl and CGI) to CGI:
AddHandler cgi-script .cgi .pl .py
This is necessary for many other things that we have in production. In order
to except my project from that, in my Apache config file I removed
Options ExecGI
and instead put
RemoveHandler .py
which now has the page showing just fine.
|
PyCharm / OS X El Capitan / Python 3.5.2 - matplotlib not working in script
Question: Python noob here, apologies if this is has an obvious answer I should know.
I'm using Python 3.5.2 via PyCharm in OSX El Capitan and I'm trying to run the
following simple script to practise with matplotlib:
import matplotlib.pyplot as plt
year = [1950,1970,1990,2010]
pop = [2.159,3.692,5.263,6.972]
plt.plot(year,pop)
plt.show()
If I execute this line by line in PyCharm's Python console, it works fine. If
I execute it as an entire script, I get this error:
/Library/Frameworks/Python.framework/Versions/3.5/bin/python3.5/Users/Cuckoo/Dropbox/Python/test.py
Traceback (most recent call last):
File "/Users/Cuckoo/Dropbox/Python/test.py", line 1, in <module>
import matplotlib.pyplot as plt
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/matplotlib/__init__.py", line 115, in <module>
import tempfile
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/tempfile.py", line 45, in <module>
from random import Random as _Random
ImportError: cannot import name 'Random'
Process finished with exit code 1
Can anyone please explain what has gone wrong and better still, how I can fix
it?
Answer: This can be caused by having another Python script in your project named
`random.py` that is overriding the original library named Random.
Try to rename or remove the `random.py` file and your script should work from
within PyCharm and the command line.
|
JSON.parse without escaping
Question: Is there anyway to do this in JavaScript:
$ cat test.json
{"body":"\u0000"}
$ python3 -c 'import json; print(json.load(open("test.json", "r")))'
{'body': '\x00'}
Notice, the data above only one `\` (does not need to be escaped). So you have
the following situation in JavaScript:
JSON.parse('{"body":"\\u0000"}') // works
JSON.parse('{"body":"\u0000"}') // does not work
With potentially any UTF-8 data comming from a binary source (websocket), can
this data be processed directly like in the first python example above?
Answer: String characters from `\u0000` through `\u001F` are considered as control
characters, and according to [RFC-7159](http://rfc7159.net/rfc7159) are not
allowed characters to use in JSON and must be escaped, as stated [in section
7](http://rfc7159.net/rfc7159#rfc.section.7).
What you are trying to do is to put unescaped control characters into a JSON,
which clearly not acceptable, you have to escape it first, non of the
languages accept it, even Python.
The correct answer would be place a UTF-8 encoded value into a string
containing a JSON format.
This is a correct JSON, and will be parsed by any JSON parser in any language,
even in JavaScript:
{"body":"\u0000"}
This is **incorrect** JSON (consider the `[NUL]` as a NUL control character,
as it cannot be represented in text):
{"body":"[NUL]"}
That's why `JSON.parse('{"body":"\\u0000"}')` works and
`JSON.parse('{"body":"\u0000"}')` doesn't.
Hope, it clarifies what's wrong with your test.
|
Django TypeError: allow_migrate() got an unexpected keyword argument 'model_name'
Question: So I copied over my Django project to a new server, replicated the environment
and imported the tables to the local mysql database.
But when I try to run makemigrations it gives me the TypeError:
allow_migrate() got an unexpected keyword argument 'model_name'
This is the full stack trace:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/base.py", line 305, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/base.py", line 353, in execute
self.check()
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/base.py", line 385, in check
include_deployment_checks=include_deployment_checks,
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/management/base.py", line 372, in _run_checks
return checks.run_checks(**kwargs)
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/checks/registry.py", line 81, in run_checks
new_errors = check(app_configs=app_configs)
File "/home/cicd/.local/lib/python2.7/site-packages/django/core/checks/model_checks.py", line 30, in check_all_models
errors.extend(model.check(**kwargs))
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/models/base.py", line 1266, in check
errors.extend(cls._check_fields(**kwargs))
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/models/base.py", line 1337, in _check_fields
errors.extend(field.check(**kwargs))
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 893, in check
errors = super(AutoField, self).check(**kwargs)
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 208, in check
errors.extend(self._check_backend_specific_checks(**kwargs))
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 310, in _check_backend_specific_checks
if router.allow_migrate(db, app_label, model_name=self.model._meta.model_name):
File "/home/cicd/.local/lib/python2.7/site-packages/django/db/utils.py", line 300, in allow_migrate
allow = method(db, app_label, **hints)
TypeError: allow_migrate() got an unexpected keyword argument 'model_name'
I would appreciate any help in debugging this error and trying to understand
what is causing this error.
Answer: I meet the same problem when i move from 1.6.* to 1.10.Finally i found the
problem cause by the **DATABASE_ROUTERS**
the old version i write like this
class OnlineRouter(object):
# ...
def allow_migrate(self, db, model):
if db == 'myonline':
return model._meta.app_label == 'online'
elif model._meta.app_label == 'online':
return False
return None
it work by rewrite like this
class OnlineRouter(object):
# ...
def allow_migrate(self, db, app_label, model_name=None, **hints):
if db == 'my_online':
return app_label == 'online'
elif app_label == 'online':
return False
return None
more detail see <https://docs.djangoproject.com/en/1.10/topics/db/multi-
db/#an-example>
|
NoSuchElement exception with Selenium even after using Wait and checking page_soure
Question: I have this simple scraper that I am running. I am trying to scrape the search
results for letter q from sam.gov:
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from bs4 import BeautifulSoup
import re
import sys
reload(sys)
sys.setdefaultencoding('utf8')
letter = 'q'
driver = webdriver.PhantomJS()
driver.set_window_size(1120, 550)
driver.get("http://sam.gov")
#element = WebDriverWait(driver, 10).until(
# EC.presence_of_element_located((By.ID, "pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1"))
# )
#element.click()
driver.find_element_by_id('pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1').click()
driver.find_element_by_id(letter).send_keys(letter)
driver.find_element_by_id('RegSearchButton').click()
def crawl():
bsObj = BeautifulSoup(driver.page_source, "html.parser")
tableList = bsObj.find_all("table", {"class":"width100 menu_header_top_emr"})
tdList = bsObj.find_all("td", {"class":"menu_header width100"})
for table in tableList:
item = table.find_all("span", {"class":"results_body_text"})
print item[0].get_text().strip() + ', ' + item[1].get_text().strip()
if driver.find_element_by_id('anch_16'):
crawl()
driver.find_element_by_id('anch_16').click()
print "Going to next page"
else:
crawl()
print "Done with last page"
driver.quit()
When i run it gives a weird error which is bothering me:
Traceback (most recent call last):
File "save.py", line 22, in <module>
driver.find_element_by_id('pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1').click()
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 269, in find_element_by_id
return self.find_element(by=By.ID, value=id_)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 752, in find_element
'value': value})['value']
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 236, in execute
self.error_handler.check_response(response)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 192, in check_response
raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchElementException: Message: {"errorMessage":"Unable to find element with id 'pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1'","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Length":"153","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:40423","User-Agent":"Python-urllib/2.7"},"httpVersion":"1.1","method":"POST","post":"{\"using\": \"id\", \"sessionId\": \"eb7dfa50-70a7-11e6-b125-9ff4e2dbd485\", \"value\": \"pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/eb7dfa50-70a7-11e6-b125-9ff4e2dbd485/element"}}
Screenshot: available via screen
I have since tried using an implicit wait of 60 right after i initialize the
browser. No luck
I have also tried webdriverwait (commented out in the code right below
`driver.get("http://sam.gov")`, and it gave me at TimeOutException.
The weird thing is if i do a `print driver.page_source` right after the get
call, the source is fine and it contains the following code which actually
contains the element with the id that I am searching for. There is no frame or
iframe either.
<a id="pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1" href="#" title="Search Records" onclick="if(typeof jsfcljs == 'function'){jsfcljs(document.getElementById('pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12'),{'pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1':'pbG220e071f_2de75f_2d417d_2d9c61_2d027d324c8fec:_viewRoot:j_id12:search1'},'');}return false" class="button">
Answer: Id locator of the element looks like dynamically generated, you should try
some different locator.
You can try using `css_selector` as below:-
driver.find_element_by_css_selector("a.button[title='Search Records']").click()
Or using `WebDriverWait` as:-
element = WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.CSS_SELECTOR, "a.button[title='Search Records']")))
element.click()
**Note** :- Before finding element make sure it's not inside any
`frame/iframe`. If it's inside any `frame/iframe` you need to switch that
`frame/iframe` before finding element as `driver.switch_to_frame("frame/iframe
id or name")`
|
Save and reset parameters of multilayer networks in theano
Question: We can save and load object in python using `six.moves.cPickle`.
I saved and reset the parameters for LeNet using the following code.
# save model
# params = layer3.params + layer2.params + layer1.params + layer0.params
import six.moves.cPickle as pickle
f = file('best_cnnmodel.save', 'wb')
pickle.dump(params, f, protocol=pickle.HIGHEST_PROTOCOL)
f.close()
# reset parameters
model_file = file('best_cnnmodel.save', 'rb')
params = pickle.load(model_file)
model_file.close()
layer3.W.set_value(params[0].get_value())
layer3.b.set_value(params[1].get_value())
layer2.W.set_value(params[2].get_value())
layer2.b.set_value(params[3].get_value())
layer1.W.set_value(params[4].get_value())
layer1.b.set_value(params[5].get_value())
layer0.W.set_value(params[6].get_value())
layer0.b.set_value(params[7].get_value())
The code seems to be ok for LeNet. But it is not elegant. For deep networks, I
can not save models using this code. What can I do in this case?
Answer: You can consider to use json format. It is human readable and easy to work
with.
Here is an example:
# Prepare the data
import json
data = {
'L1' : { 'W': layer1.W, 'b': layer1.b },
'L2' : { 'W': layer2.W, 'b': layer2.b },
'L3' : { 'W': layer3.W, 'b': layer3.b },
}
json_data = json.dumps(data)
The `json_data` looks like this:
{"L2": {"b": 2, "W": 17}, "L3": {"b": 2, "W": 10}, "L1": {"b": 2, "W": 1}}
# Unpack the data
params = json.loads(json_data)
for k, v in params.items():
level = int(k[1:])
# assume you save the layer in an array, but you can use
# different way to store and reference the layers
layer = layers[level]
layer.W = v['W']
layer.b = v['b']
|
Error tokenizing data
Question: This is my code:
import pandas
import datetime
from decimal import Decimal
file_ = open('myfile.csv', 'r')
result = pandas.read_csv(
file_, header=None,
names=('sec', 'date', 'sale', 'buy'),
usecols=('date', 'sale', 'buy'),
parse_dates=['date'],
iterator=True,
chunksize=100,
compression=None,
engine="c",
date_parser=lambda dt: datetime.datetime.strptime(dt, '%Y%m%d %H:%M:%S.%f'),
converters={'sale': (lambda u: Decimal(u)), 'buy': (lambda u: Decimal(u))}
)
And then I try...
result.get_chunk()
Only to get an error like this:
CParserError: Error tokenizing data. C error: Expected 3 fields in line 3, saw 4
From a file like this (I just show the first 4 lines - the file has no header,
and all the lines have this format):
EUR/USD,20160701 00:00:00.071,1.11031,1.11033
EUR/USD,20160701 00:00:00.255,1.11031,1.11033
EUR/USD,20160701 00:00:00.256,1.11025,1.11033
EUR/USD,20160701 00:00:00.258,1.11027,1.11033
... > l0.000.000 lines like these
My intention is to get an object to iterate by chunks and not have the whole
crap in memory (the actual file has 560mb!). I want to discard the first
column (there are 4 columns but since this file has the same value in the
first column, I want to discard such column). I want to keep columns 1, 2, and
3 (discarding 0) as date, sale, and purchase price.
Actually this is my first attempt with pandas, since the former solution used
standard Python csv module, and takes a lot of time.
What am I missing? Why am I getting such error?
Answer:
#try this code
import pandas as pd
import numpy as np
import csv
# To print only three columns , create a data frame,to do that give names to columns in csv file with ',' as seperator
myfile.csv:
sec,date,sale,buy
EUR/USD,20160701 00:00:00.071,1.11031,1.11033
EUR/USD,20160701 00:00:00.255,1.11031,1.11033
EUR/USD,20160701 00:00:00.256,1.11025,1.11033
EUR/USD,20160701 00:00:00.258,1.11027,1.11033
data = pd.read_csv('myfile.csv',sep=',')
df = pd.DataFrame({'date':data.date,'sale':data.sale,'buy':data.buy})
print(df)
output:
buy date sale
0 1.11033 20160701 00:00:00.071 1.11031
1 1.11033 20160701 00:00:00.255 1.11031
2 1.11033 20160701 00:00:00.256 1.11025
3 1.11033 20160701 00:00:00.258 1.11027
|
Customize username and password field in Django?
Question: First, How can I set `min_length` for `username`?
`ChachaUser._meta.get_field('username').min_length = 2` doesn't work.
Second, How can I place `placeholder` for `password1` and `password2`?
`forms.PasswordInput(attrs={'placeholder' : "6μ리 μ΄μ"}),` doesn't work.
This is my customized `User` model and `UserCreationForm`.
`models.py`
from django.core.validators import RegexValidator
from django.contrib.auth.models import AbstractUser
from django.db import models
GENDER_CHOICES = (
('M', 'λ¨'),
('F', 'μ¬'),
)
phone_regex = RegexValidator(
regex=r'^\d{11}$',
message=" '-' μμ΄ μ
λ ₯ν΄μ£ΌμΈμ",
)
username_regex = RegexValidator(
regex=r'^[0-9a-zA-Z]*$',
message='μμ΄λλ μμ΄μ μ«μλ‘λ§ κ΅¬μ±λμ΄μΌ ν©λλ€.'
)
class ChachaUser(AbstractUser):
birth = models.DateField("μλ
μμΌ")
name = models.CharField(
"μ΄ λ¦",
max_length=4
)
gender = models.CharField(
"μ± λ³",
max_length=1,
choices=GENDER_CHOICES,
default='M'
)
phone_number = models.CharField(
"νΈλν°",
validators=[phone_regex],
max_length=11
)
job = models.CharField(
"μ§ μ
",
max_length=20,
)
# python manage.py createsuperuser ν λ λμ€λ νλͺ©
REQUIRED_FIELDS = [
'birth',
'name',
'gender',
'phone_number',
'job',
'email'
]
ChachaUser._meta.get_field('username').verbose_name = 'μμ΄λ'
ChachaUser._meta.get_field('username').validators = [username_regex]
ChachaUser._meta.get_field('username').max_length = 20
ChachaUser._meta.get_field('username').min_length = 2
`forms.py`
from django import forms
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth import get_user_model
class MyUserCreationForm(UserCreationForm):
birth = forms.DateField(
label="μλ
μμΌ",
widget=forms.SelectDateWidget(
years=range(1970, 2015)
),
)
class Meta(UserCreationForm.Meta):
model = get_user_model()
fields = UserCreationForm.Meta.fields + (
'name',
'gender',
'birth',
'phone_number',
'job',
)
exclude = ('email', )
widgets = {
'username' : forms.TextInput(
attrs={'placeholder': 'μνλ²³, μ«μλ§ κ°λ₯(20μ μ΄λ΄)'}
),
'phone_number' : forms.TextInput(
attrs={'placeholder' : "ex) 01012341234"}
),
'job' : forms.TextInput(
attrs={'placeholder' : "ex) νκ΅λ μ² νκ³Ό, μ μλ λ±(20μ μ΄λ΄)"}
),
'password1' : forms.PasswordInput(
attrs={'placeholder' : "6μ리 μ΄μ"}
),
'password2' : forms.PasswordInput(
attrs={'placeholder' : "6μ리 μ΄μ"}
),
}
Answer: For first question:
from django.core import validators
class ChachaUser(AbstractUser):
..................
AbstractUser._meta.get_field('username').validators=[validators.MinLengthValidator(2)]
For second question your couldn't change `password1` in `Meta.widgets` because
it is not a model field. You can override widget in `__init__` method instead.
|
print current thread in python 3
Question: I have this script:
import threading, socket
for x in range(800)
send().start()
class send(threading.Thread):
def run(self):
while True:
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("www.google.it", 80))
s.send ("test")
print ("Request sent!")
except:
pass
And at the place of "Request sent!" I would like to print something like:
"Request sent! %s" % (the current number of the thread sending the request)
What's the fastest way to do it?
**\--SOLVED--**
import threading, socket
for x in range(800)
send(x+1).start()
class send(threading.Thread):
def __init__(self, counter):
threading.Thread.__init__(self)
self.counter = counter
def run(self):
while True:
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("www.google.it", 80))
s.send ("test")
print ("Request sent! @", self.counter)
except:
pass
Answer: You could pass your counting number (`x`, in this case), as a variable in your
send class. Keep in mind though that `x` will start at 0, not 1.
for x in range(800)
send(x+1).start()
class send(threading.Thread):
def __init__(self, count):
self.count = count
def run(self):
while True:
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("www.google.it", 80))
s.send ("test")
print ("Request sent!"), self.count
except:
pass
Or, as Rob commented above in the other question,
[`threading.current_thread()`](http://docs.python.org/library/threading.html#threading.current_thread)
looks satisfactory.
|
How to plot data from multiple files in a loop using matplotlib in python?
Question: I have a more than 1000 files which are .CSV (data_1.csv......data1000.csv),
each containing X and Y values !
x1 y1 x2 y2
5.0 60 5.5 500
6.0 70 6.5 600
7.0 80 7.5 700
8.0 90 8.5 800
9.0 100 9.5 900
* * *
I have made a subplot program in python which can give two plots
(plot1-X1vsY1, Plot2-X2vsY2) at a time using one file. I need help in looping
all the files, (open a file, read it, plot it, pick another file, open it,
read it, plot it, then next ..... till all the files in a folder gets plotted)
## I have made a small code:
import pandas as pd
import matplotlib.pyplot as plt
df1=pd.read_csv("data_csv",header=1,sep=',')
fig = plt.figure()
plt.subplot(2, 1, 1)
plt.plot(df1.iloc[:,[1]],df1.iloc[:,[2]])
plt.subplot(2, 1, 2)
plt.plot(df1.iloc[:,[3]],df1.iloc[:,[4]])
plt.show()
Any loop structure to do this task more efficiently ??
Answer: You can generate a list of filenames using `glob` and then plot them in a for
loop.
import glob
import matplotlib.pyplot as plt
files = glob.glob(# file pattern something like '*.csv')
for file in files:
df1=pd.read_csv(file,header=1,sep=',')
fig = plt.figure()
plt.subplot(2, 1, 1)
plt.plot(df1.iloc[:,[1]],df1.iloc[:,[2]])
plt.subplot(2, 1, 2)
plt.plot(df1.iloc[:,[3]],df1.iloc[:,[4]])
plt.show() # this wil stop the loop until you close the plot
|
How can I set infinity as an element of a matrix in python(numpy)?
Question: This is the program
import numpy as n
m = complex('inf')
z=n.empty([2,2] , dtype = complex)
z=n.array(input() , dtype = complex )
but in the console when i give 'm' as an input i get the following error
massage: 'NameError: name 'm' is not defined'
Answer: Infinity in python can be typed as:
float('inf') / float('-inf')
or simply as a number
1e500 (+inf)
-1e500 (-inf)
|
Convert bash script to python
Question: I have a bash script and i want to convert it to python.
This is the script :
mv $1/positive/*.$3 $2/JPEGImages
mv $1/negative/*.$3 $2/JPEGImages
mv $1/positive/annotations/*.xml $2/Annotations
mv $1/negative/annotations/*.xml $2/Annotations
cut -d' ' -f1 $1/positive_label.txt > $4_trainval.txt
My problem is : i didn't found how to past positive_label.txt in
$4_trainval.txt.
This is my try, it's the first time i work with python. please help me to make
it work. thank you.
import sys # Required for reading command line arguments
import os # Required for path manipulations
from os.path import expanduser # Required for expanding '~', which stands for home folder. Used just in case the command line arguments contain "~". Without this, python won't parse "~"
import glob
import shutil
def copy_dataset(arg1,arg2,arg3,arg4):
path1 = os.path.expanduser(arg1)
path2 = os.path.expanduser(arg2) #
frame_ext = arg3 # File extension of the patches
pos_files = glob.glob(os.path.join(path1,'positive/'+'*.'+frame_ext))
neg_files = glob.glob(os.path.join(path1,'negative/'+'*.'+frame_ext))
pos_annotation = glob.glob(os.path.join(path1,'positive/annotations/'+'*.'+xml))
neg_annotation = glob.glob(os.path.join(path1,'negative/annotations/'+'*.'+xml))
#mv $1/positive/*.$3 $2/JPEGImages
for x in pos_files:
shutil.copyfile(x, os.path.join(path2,'JPEGImages'))
#mv $1/negative/*.$3 $2/JPEGImages
for y in neg_files:
shutil.copyfile(y, os.path.join(path2,'JPEGImages'))
#mv $1/positive/annotations/*.xml $2/Annotations
for w in pos_annotation:
shutil.copyfile(w, os.path.join(path2,'Annotations'))
#mv $1/negative/annotations/*.xml $2/Annotations
for z in neg_annotation:
shutil.copyfile(z, os.path.join(path2,'Annotations'))
#cut -d' ' -f1 $1/positive_label.txt > $4_trainval.txt
for line in open(path1+'/positive_label.txt')
line.split(' ')[0]
Answer: Without testing, something like that should works.
#cut -d' ' -f1 $1/positive_label.txt > $4_trainval.txt
positive = path1+'/positive_label.txt'
path4 = os.path.join(arg4, '_trainval.txt')
with open(positive, 'r') as input_, open(path4, 'w') as output_:
for line in input_.readlines():
output_.write(line.split()[0] + "\n")
This code defines the two files we will work with and opens both. The first is
opened in read mode, the second in write mode. For each line in the _input_
file, we write the first find data separated by a space to the _output_ file.
Check [Reading and Writing Files in
Python](http://www.pythonforbeginners.com/files/reading-and-writing-files-in-
python) for more informations about files into Python.
|
Python tkinter's entry.get() does not work, how can I fix it?
Question: I am building a simple program for university. We have to convert our code to
an interface. Ive managed to make the interface, but i cant seem to pass my
values from Entry to the actual code. Here is my code:
import sys
from tkinter import *
from tkinter import ttk
import time
from datetime import datetime
now= datetime.now()
d = dict()
def quit():
print("Have a great day! Goodbye :)")
sys.exit(0)
def display():
print(str(d))
def add(*args):
global stock
global d
stock = stock_Entry.get()
Quantity = Quantity_Entry.get()
if stock not in d:
d[stock] = Quantity
else:
d[stock] += Quantity
root = Tk()
root.title("Homework 5 216020088")
mainframe = ttk.Frame(root, padding="6 6 20 20")
mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
ttk.Label(mainframe, text="you are accesing this on day %s of month %s of %s" % (now.day,now.month,now.year)+" at exactly %s:%s:%s" % (now.hour,now.minute,now.second), foreground="yellow", background="Black").grid(column=0, row = 0)
stock_Entry= ttk.Entry(mainframe, width = 60, textvariable="stock").grid(column=0, row = 1, sticky=W)
ttk.Label(mainframe, text="Please enter the stock name").grid(column=1, row = 1, sticky=(N, W, E, S))
Quantity_Entry= ttk.Entry(mainframe, width = 60, textvariable="Quantity").grid(column=0, row = 2, sticky=W)
ttk.Label(mainframe, text="Please enter the quantity").grid(column=1, row = 2, sticky=(N, W, E, S))
ttk.Button(mainframe, text="Add", command=add).grid(column=0, row=3, sticky=W)
ttk.Button(mainframe, text="Display", command=display).grid(column=0, row=3, sticky=S)
ttk.Button(mainframe, text="Exit", command=quit).grid(column=0, row=3, sticky=E)
for child in mainframe.winfo_children(): child.grid_configure(padx=5, pady=5)
root.mainloop()
Answer: You cannot create the widget and grid it at the same time like this, if you
still need to access it later. `stock_Entry.get()` will raise an
`AttributeError` (`NoneType`).
Instead of:
stock_Entry= ttk.Entry(mainframe, width = 60, textvariable="stock").grid(column=0, row = 1, sticky=W)
use:
stock_Entry = ttk.Entry(mainframe, width = 60, textvariable="stock")
stock_Entry.grid(column=0, row = 1, sticky=W)
Same for the `Quantity_Entry`:
Quantity_Entry = ttk.Entry(mainframe, width = 60, textvariable="Quantity")
Quantity_Entry.grid(column=0, row = 2, sticky=W)
...and it works:
[](http://i.stack.imgur.com/q6i7A.png)
|
cmd module - python
Question: I am trying to build a python shell using cmd module.
from cmd import Cmd
import subprocess
import commands
import os
from subprocess import call
class Pirate(Cmd):
intro = 'Welcome to shell\n'
prompt = 'platform> '
pass
if __name__ == '__main__':
Pirate().cmdloop()
I am trying to build a shell using python - cmd module. I am trying to build
these two functionalities.
Welcome to shell
platform> ls
platform> cd ..
like if I want to perform ls - list all files from that directory in my python
shell or cd .. - go back to prev directory
Can anyone help in this? I tried using subprocess library.. but didn't get it
working.
Appreciate your help ! Ref Doc: <https://docs.python.org/3/library/cmd.html>
Answer: I have a hard time trying to figure out why you would need such a thing, but
here's my attempt:
import subprocess
from cmd import Cmd
class Pirate(Cmd):
intro = 'Welcome to shell\n'
prompt = 'platform> '
def default(self, line): # this method will catch all commands
subprocess.call(line, shell=True)
if __name__ == '__main__':
Pirate().cmdloop()
The main point is to use `default` method to catch all commands passed as
input.
|
Easily editing base class variables from inherited class
Question: ### How does communication between base classes and inherited classes work?
I have a data class in my python code ( storing all important values, duh ), I
tried inheriting new subclasses from the _data base class_ , everything worked
fine except the fact that the classes were not actually communicating ( when
one class variable was changed in a subclass, the class attribute **was not**
changed in the base class nor any other subclasses.
I guess I just failed to understand how inheritance works, **my question is**
: Does inheritance keep any connection to the base classes, or are the values
set at the time of inheritance?
If there is any connection, how do you easily manipulate base class variables
from a subclass ( I tried it with the _cls_ variable to access base class
variables, didn't work out )
### Example
class Base:
x = 'baseclass var' # The value I want to edit
class Subclass(Base):
@classmethod(cls)
???edit_base_x_var_here??? # This is the part I don't know
Answer: Well, you could do that in this way:
class Base:
x = 'baseclass var' # The value I want to edit
class Subclass(Base):
@classmethod
def change_base_x(cls):
Base.x = 'nothing'
print Subclass.x
Subclass.change_base_x()
print Subclass.x
furthermore, you don't have to use `@classmethod`, it could be staticmethod,
because you don't need current class object `cls`:
class Base:
x = 'baseclass var' # The value I want to edit
class Subclass(Base):
@staticmethod
def change_base_x():
Base.x = 'nothing'
EDITED:
According to your question, about other way. Yes it is, but not so pretty. I
would say more. If you want to change variable of base class, then you will do
it globally though, so that option with assigning to `Base.x` is the best way
you can achieve that.
|
Python: indexing letters of string in a list
Question: I would like to ask if there is a way how to get exact letters of some string
stored in a list? I'm working with DNA strings, get them from FASTA file using
BioPython SeqIO and store them as strings in a list. In next step I will
convert it to numerical sequence (called genomic signals). But as novice in
Python I don't know how to obtain it from the list correctly. Should I use
different data type?
In Maltab I used:
a=1+1i;c=-1-1i;g=-1+1i;t=1-1i; %base values definition
for i=1:number of sequences
length_of_sequence(i)=length(sequence{1,i});
temp=zeros(1,length_of_sequence(i),'double');
temp(sequence{i}=='A')=angle(a);
temp(sequence{i}=='C')=angle(c);
temp(sequence{i}=='G')=angle(g);
temp(sequence{i}=='T')=angle(t);
KontigNumS{i,1}=cumsum(temp); %cumulated phase of whole vector
end
what creates a vector and replace zeros with according values. I wasn't able
to find a similar question. Thanks for replies.
My python code:
#Dependencies
from Bio import SeqIO #fasta loading
import cmath #complex numbers
import numpy as np
#Open FASTA file new variable
lengths=list()
sequences=list()
handle=open("F:\GC_Assembler_Python\xx.fasta","r")
for record in SeqIO.parse(handle, "fasta"):
print(record.id)
print(len(record.seq))
lengths.append(len(record.seq))
sequences.append(str(record.seq))
#Convert to genomic signals
a=complex(1,1)
c=complex(-1,-1)
g=complex(-1,1)
t=complex(1,-1)
I stopped here.
Answer: I don't know how MATLAB does it. In Python you can access any position in a
string without converting to a list:
DNA = "ACGTACGTACGT"
print(DNA[2])
# outputs "G", the third base
If you want to store "strings in a list" you can do this:
DNA_list = ["AAAAAA", "CCCCC", "GGGGG", "TTTTT"]
print(DNA_list[0][0])
# outputs "A", the first "A" of the first sequence
print(DNA_list[1][0])
# outputs "C", the first "C" of the second sequence
|
Python - Parsing Json format input
Question: I need to make a data parsing that come from another program in JSON format:
import json
input = '''
Array
(
[error] => Array
(
)
[result] => Array
(
[0] => Person Object
(
[arr:Person:private] => Array
(
[cf] => DRGMRO75P03G273O
[first_name] => Mario
[last_name] => Dragoni
[email] => [email protected]
[phone] => 558723
[uid] => dragom
[source] => USRDATA
)
)
)
)
'''
I tried:
data = json.loads(input)
But I get:
**ValueError:** No JSON object could be decoded
Perhaps the fault is due to lack of field separators?
Edit:
The input was generated by a _php_ **print_r** , I replaced it with
**json_encode**
Answer: your function is correct.
but the provided json string is wrong
in fact the input is a mixed array and class object
you can import json in python like this:
import json
j = json.loads('{"one" : "1", "two" : "2", "three" : "3"}')
print j['two']
|
Custom date string to Python date object
Question: I am using Scrapy to parse data and getting date in `Jun 14, 2016 ` format, I
have tried to parse it with `datetime.strftime` but
what approach should I use to convert custom date strings and what to do in my
case.
**UPDATE**
I want to parse UNIX timestamp to save in database.
Answer: Something like this should work:
import time
import datetime
datestring = "September 2, 2016"
unixdatetime = int(time.mktime(datetime.datetime.strptime(datestring, "%B %d, %Y").timetuple()))
print(unixdatetime)
Returns: `1472792400`
|
Pythonic way to find if an IP in a list belongs to a different subnet
Question: I have a script that generates the configuration for some campus wireless
mobility switches. The user needs to supply a set of IP addresses for the
configuration.
Among other constraints, these IP's must all be in the same /24 subnet (always
/24). To avoid typos where an IP is in a different subnet (which messes up the
configuration and it happened already), I would like to tell the user which IP
is at fault. I wrote the following, but I feel there could be a better way to
do it.
Suppose the list is this, where the 3rd IP is wrong:
ips = ['10.0.0.1', '10.0.0.2', '10.0.10.3', '10.0.0.4', '10.0.0.5']
The following gets the job done:
subnets = set()
for ip in ips:
subnets.add('.'.join(ip.split('.')[0:3]))
# This would result in subnet being set(['10.0.10', '10.0.0'])
if len(subnets) > 1:
seen_subnets = defaultdict(list)
for sn in subnets:
for ip in ips:
if sn in ip:
seen_subnets[sn].append(ip)
suspect = ''
for sn in seen_subnets.keys():
if len(seen_subnets[sn]) == 1:
suspect = seen_subnets[sn][0]
if not suspect:
# Do something to tell the user one or more IP's are incorrect
# but I couldn't tell which ones
**NOTE:** The smallest list that I could have has 3 items, and I'm basing this
on the assumption that probably most if not all mistakes will be just 1 IP.
Is there perhaps a more straightforward way to do this? I feel the solution
has to be based on using a `set` either way but it didn't seem to me any of
its methods would be more helpful than this.
Answer: Something like this would work:
from itertools import groupby
ips = ['10.0.0.1', '10.0.0.2', '10.0.10.3', '10.0.0.4', '10.0.0.5']
def get_subnet(ip):
return '.'.join(ip.split('.')[:3])
groups = {} # group ips by subnet
for k, g in groupby(sorted(ips), key=get_subnet):
groups[k] = list(g)
# Sort the groups by most common first
for row, (subnet, ips) in enumerate(
sorted(groups.iteritems(), key=lambda (k, v): len(v), reverse=True)
):
if row > 0: # not the most common subnet
print('You probably entered these incorrectly: {}'.format(ips))
|
Python Failed to Verify any CRLs for SSL/TLS connections
Question: In Python 3.4, a `verify_flags` that can be used to check if a certificate was
revoked against CRL, by set it to `VERIFY_CRL_CHECK_LEAF` or
`VERIFY_CRL_CHECK_CHAIN`.
I wrote a simple program for testing. But on my systems, this script failed to
verify ANY connections even if it's perfectly valid.
import ssl
import socket
def tlscheck(domain, port):
addr = domain
ctx = ssl.create_default_context()
ctx.options &= ssl.CERT_REQUIRED
ctx.verify_flags = ssl.VERIFY_CRL_CHECK_LEAF
ctx.check_hostname = True
#ctx.load_default_certs()
#ctx.set_default_verify_paths()
#ctx.load_verify_locations(cafile="/etc/ssl/certs/ca-certificates.crt")
sock = ctx.wrap_socket(socket.socket(), server_hostname=addr)
sock.connect((addr, port))
import pprint
print("TLS Ceritificate:")
pprint.pprint(sock.getpeercert())
print("TLS Version:", sock.version())
print("TLS Cipher:", sock.cipher()[0])
exit()
tlscheck("stackoverflow.com", 443)
My code always quits with `ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED]
certificate verify failed (_ssl.c:645)`.
First I suspected that the certificate database was not loaded properly. But
after I tried `load_default_certs()`, `set_default_verify_paths()`,
`load_verify_locations(cafile="/etc/ssl/certs/ca-certificates.crt")`, and none
of them worked.
Also, `ctx.options &= ssl.CERT_REQUIRED` works as expected, it can tell if a
certificate chain is trusted or not. But not for CRLs... It also indicates
that my CAs are correct.
I know "/etc/ssl/certs/ca-certificates.crt" contains valid CAs. What is the
problem?
Answer: To check against CRL you have to manually download the CRL and put them in the
right place so that the underlying OpenSSL library will find it. There is no
automatic downloading of CRL and specifying the place where to look for the
CRL is not intuitive either. What you can do:
* get the CRL distribution points from the certificate. For stackoverflow.com one is <http://crl3.digicert.com/sha2-ha-server-g5.crl>
* download the current CRL from there
* convert it from the DER format to PEM format, because this is what is expected in the next step:
`openssl crl -inform der -in sha2-ha-server-g5.crl > sha2-ha-
server-g5.crl.pem`
* add the location to the verify_locations:
`ctx.load_verify_locations(cafile="./sha2-ha-server-g5.crl.pem")`
This way you can verify the certificate against the CRL.
|
missing last bin in histogram plot from matplot python
Question: I'm trying to draw histrogram based of my value
x = ['3', '1', '4', '1', '5', '9', '2', '6', '5', '3', '5',
'2', '3', '4', '5', '6', '4', '2', '0', '1', '9', '8',
'8', '8', '8', '8', '9', '3', '8', '0', '9', '5', '2',
'5', '7', '2', '0', '1', '0', '6', '5']
x_num = [int(i) for i in x]
key = '0123456789'
for i in key:
print(i," count =>",x.count(i))
plt.hist(x_num, bins=[0,1,2,3,4,5,6,7,8,9])
[](http://i.stack.imgur.com/wZK0l.png)
The last 2 numbers "8, 9" bin should have distribution count of 6 , 4 But in
histogram it combine 8 and 9 and get value of 10 instead of separate them.
Total number of bin should be 10 => but it only giving me graph of 9..
How could I separate them and break 8 and 9 ?
Answer:
import matplotlib.pyplot as plt
x = ['3', '1', '4', '1', '5', '9', '2', '6', '5', '3', '5',
'2', '3', '4', '5', '6', '4', '2', '0', '1', '9', '8',
'8', '8', '8', '8', '9', '3', '8', '0', '9', '5', '2',
'5', '7', '2', '0', '1', '0', '6', '5']
x_num = [int(i) for i in x]
key = '0123456789'
for i in key:
print(i, " count =>", x.count(i))
plt.hist(x_num, bins=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10])
plt.show()
|
Whitenoise, Mezzanine, Django -ImportError: cannot import name ManifestStaticFilesStorage
Question: I am trying to deploy my mezzanine project on heroku. The last error gives me
an ultimate stack- ImportError: cannot import name ManifestStaticFilesStorage.
Here is my core project structure:
βββ deploy
βΒ Β βββ crontab
βΒ Β βββ gunicorn.conf.py.template
βΒ Β βββ local_settings.py.template
βΒ Β βββ nginx.conf
βΒ Β βββ supervisor.conf
βββ dev.db
βββ fabfile.py
βββ flat
βΒ Β βββ admin.py
βΒ Β βββ admin.pyc
βΒ Β βββ __init__.py
βΒ Β βββ __init__.pyc
βΒ Β βββ models.py
βΒ Β βββ models.pyc
βΒ Β βββ tests.py
βΒ Β βββ views.py
βΒ Β βββ views.pyc
βββ __init__.py
βββ __init__.pyc
βββ manage.py
βββ Procfile
βββ README.md
βββ requirements.txt
βββ runtime.txt
βββ settings.py
βββ staticfiles -> mezzanine_heroku/staticfiles
βββ urls.py
βββ urls.pyc
βββ wsgi.py
wsgi.py:
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "settings")
from django.core.wsgi import get_wsgi_application
from whitenoise.django import DjangoWhiteNoise
application = get_wsgi_application()
application = DjangoWhiteNoise(application)
Procfile:
web: gunicorn wsgi
Traceback from heroku-logs:
ImportError: cannot import name ManifestStaticFilesStorage
2016-09-02T18:02:36.124458+00:00 app[web.1]: Traceback (most recent call last):
2016-09-02T18:02:36.124494+00:00 app[web.1]: File "/app/.heroku/python/bin/gunicorn", line 11, in <module>
2016-09-02T18:02:36.124529+00:00 app[web.1]: sys.exit(run())
2016-09-02T18:02:36.124558+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 74, in run
2016-09-02T18:02:36.124620+00:00 app[web.1]: WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
2016-09-02T18:02:36.124646+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/app/base.py", line 192, in run
2016-09-02T18:02:36.124706+00:00 app[web.1]: super(Application, self).run()
2016-09-02T18:02:36.124709+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/app/base.py", line 72, in run
2016-09-02T18:02:36.124754+00:00 app[web.1]: Arbiter(self).run()
2016-09-02T18:02:36.124800+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/arbiter.py", line 218, in run
2016-09-02T18:02:36.124858+00:00 app[web.1]: self.halt(reason=inst.reason, exit_status=inst.exit_status)
2016-09-02T18:02:36.124862+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/arbiter.py", line 331, in halt
2016-09-02T18:02:36.124962+00:00 app[web.1]: self.stop()
2016-09-02T18:02:36.124966+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/arbiter.py", line 381, in stop
2016-09-02T18:02:36.125047+00:00 app[web.1]: time.sleep(0.1)
2016-09-02T18:02:36.125057+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/arbiter.py", line 231, in handle_chld
2016-09-02T18:02:36.125138+00:00 app[web.1]: self.reap_workers()
2016-09-02T18:02:36.125141+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/gunicorn/arbiter.py", line 506, in reap_workers
2016-09-02T18:02:36.125241+00:00 app[web.1]: raise HaltServer(reason, self.WORKER_BOOT_ERROR)
2016-09-02T18:02:36.125304+00:00 app[web.1]: gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>
2016-09-02T18:02:36.182785+00:00 heroku[web.1]: State changed from starting to crashed
2016-09-02T18:02:36.175782+00:00 heroku[web.1]: Process exited with status 1
Most confusing is the `ImportError: cannot import name
ManifestStaticFilesStorage` error.
Answer: ManifestStaticFilesStorage was introduced in Django 1.7. Are you using an
older version of Django? If so, you should upgrade to a [supported
version](https://www.djangoproject.com/download/#supported-versions).
It's still possible to use [WhiteNoise
2.0.6](http://whitenoise.evans.io/en/legacy-2.x/) with older versions of
Django, but this is not supported by either me or the Django team.
|
How to configure a package in PyPI to install only with pip3
Question: I distributed my package written in Python 3 on PyPI. It can be installed by
both `pip2` and `pip3`. How can I configure the package to only be available
in Python 3; i.e. to install only with `pip3`?
I've already added these classifiers in `setup.py` file:
classifiers=[
...
# Supported Python versions.
'Programming Language :: Python :: 3',
'Programming Language :: Python :: 3.4',
'Programming Language :: Python :: 3.5',
...
]
But it still can be installed by `pip2`.
Answer: I'm not sure if such an option exists. What you could do though is manually
enforce it by checking that the version of python in which it is installed is
larger than the version you want to dictate:
from sys import version_info
class NotSupportedException(BaseException): pass
if version_info.major < 3:
raise NotSupportedException("Only Python 3.x Supported")
While this won't stop it being reached from `pip2` it should stump any users
trying to use an old version of Python
|
Trying to output the x most common words in a text file
Question: I'm trying to write a program that will read in a text file and output a list
of most common words (30 as the code is written now) along with their counts.
so something like:
word1 count1
word2 count2
word3 count3
... ...
... ...
wordn countn
in order of count1 > count2 > count3 >... >countn. This is what I have so far
but I cannot get the sorted function to perform what I want. The error I get
now is:
TypeError: list indices must be integers, not tuple
I'm new to python. Any help would be appreciated. Thank you.
def count_func(dictionary_list):
return dictionary_list[1]
def print_top(filename):
word_list = {}
with open(filename, 'r') as input_file:
count = 0
#best
for line in input_file:
for word in line.split():
word = word.lower()
if word not in word_list:
word_list[word] = 1
else:
word_list[word] += 1
#sorted_x = sorted(word_list.items(), key=operator.itemgetter(1))
# items = sorted(word_count.items(), key=get_count, reverse=True)
word_list = sorted(word_list.items(), key=lambda x: x[1])
for word in word_list:
if (count > 30):#19
break
print "%s: %s" % (word, word_list[word])
count += 1
# This basic command line argument parsing code is provided and
# calls the print_words() and print_top() functions which you must define.
def main():
if len(sys.argv) != 3:
print 'usage: ./wordcount.py {--count | --topcount} file'
sys.exit(1)
option = sys.argv[1]
filename = sys.argv[2]
if option == '--count':
print_words(filename)
elif option == '--topcount':
print_top(filename)
else:
print 'unknown option: ' + option
sys.exit(1)
if __name__ == '__main__':
main()
Answer: Use the
[`collections.Counter`](https://docs.python.org/3/library/collections.html#collections.Counter)
class.
from collections import Counter
for word, count in Counter(words).most_common(30):
print(word, count)
Some unsolicited advice: Don't make so many functions until everything is
working as one big block of code. Refactor into functions _after_ it works.
You don't even need a main section for a script this small.
|
Python: Ignore case sensitivity for MYSQL column names
Question: I am querying my MySQL DB with following code.
import MySQLdb
db = MySQLdb.connect("localhost","user","password","test" )
cursor = db.cursor(MySQLdb.cursors.DictCursor)
sql = "select * from student"
try:
cursor.execute(sql)
results = cursor.fetchall()
for row in results:
print row['firstname']
except:
print "Error: unable to fecth data"
db.close()
Problem is that the column name specified in `row['firstName']` does not match
and is case sensitive. Is there any way to ignore case sensitivity?
Answer: you can use this:
sequence = cursor.column_names
<https://dev.mysql.com/doc/connector-python/en/connector-python-api-
mysqlcursor-column-names.html>
Then compare your string to the actual name with .lower() and act accordingly
|
Python background shell script communication
Question: I have 2 python scripts, `foo.py` and `bar.py`. I am running foo.py in the
background using
python foo.py &
Now I want to run `bar.py` and use the stdout from this file to trigger script
inside foo.py. Is this possible? I'm using Ubuntu 16.04 LTS.
Answer: You could use [UNIX named pipe](https://en.wikipedia.org/wiki/Named_pipe) for
that.
First, you create named pipe object by executing `mkfifo named_pipe` in the
same directory, where you have your python files.
Your `foo.py` then could look like this:
while True:
for line in open('named_pipe'):
print 'Got: [' + line.rstrip('\n') + ']'
And your `bar.py` could look like this:
import sys
print >>open('named_pipe', 'wt'), sys.argv[-1]
So, you run your consumer process like this: `python foo.py &`. And finally,
each time you execute `python bar.py Hello`, you will see the message `Got:
[Hello]` in your console.
UPD: unlike Paul's answer, if you use _named_ pipe, you don't have to start
one of the processes from inside the other.
|
Getting the root word using the Wordnet Lemmatizer
Question: I need to find a common root word matched for all related words for a keyword
extractor.
How to convert words into the same root using the python nltk lemmatizer?
* Eg:
1. generalized, generalization -> general
2. optimal, optimized -> optimize (maybe)
3. configure, configuration, configured -> configure
The python nltk lemmatizer gives 'generalize', for 'generalized' and
'generalizing' when part of speech(pos) tag parameter is used but not for
'generalization'.
Is there a way to do this?
Answer: Use SnowballStemmer:
>>> from nltk.stem.snowball import SnowballStemmer
>>> stemmer = SnowballStemmer("english")
>>> print(stemmer.stem("generalized"))
general
>>> print(stemmer.stem("generalization"))
general
> Note: Lemmatisation is closely related to stemming. The difference is that a
> stemmer operates on a single word without knowledge of the context, and
> therefore cannot discriminate between words which have different meanings
> depending on part of speech.
A general issue I have seen with lemmatizers is that it identifies even bigger
words as _lemma_ s.
Example: In WordNet Lemmatizer(checked in NLTK),
* Genralized => Generalize
* Generalization => Generalization
* Generalizations => Generalization
POS tag was not given as input in the above cases, so it was always considered
_noun_.
|
matplotlib.use required before other imports clashes with pep8. Ignore or fix?
Question: I have a pythonscript that starts like this:
#!/usr/bin/env python
import matplotlib
matplotlib.use("Agg")
from matplotlib.dates import strpdate2num
import numpy as np
import pylab as pl
from cmath import rect, phase
It works like a charm, but my editor complains: `E402 module level import not
at top of file [pep8]`.
If I move the `matplotlib.use("Agg")` down, the script will not work.
Should I just ignore the error? Or is there a way to fix this?
**EDIT :** I'm aware that PEP8 says that this is only a suggestion and it may
be ignored, but I'm hoping that there exists a nice way to initialise modules
without breaking PEP8 guidelines, as I don't think I can make my editor ignore
this rule on a per-file-basis.
**EDIT2 :** I'm using Atom with linter-pylama
Answer: The solution depends on the `linter` that is being used.
In my case I am using `pylama`
The manual for this `linter` suggests adding `# noqa` to the end of a line
containing an error you wish to suppress.
Other linters will have different mechanisms.
|
Python Shellexecute windows api with Ctypes over TCP/IP
Question: I have question about running windows API's over TCP/IP protocol. For example,
I want to bring remote machine's cmd.exe to other machine (Like Netcat, fully
simulating cmd.exe over TCP/IP) . I searched online for doing it with python
but couldn't find anything helpful. I can do this using subprocess and other
python capabilities but it lacks user-interface problem. I used this kind of
code:
import socket
import subprocess
import ctypes
HOST = '192.168.1.22'
PORT = 443
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
while 1:
#send initial cmd.exe banner to remote machine
s.send(ctypes.windll.Shell32.ShellExecuteA(None,"open","cmd.exe",None,None,0))
#accept user input
data = s.recv(1024)
#pass it again to Shellexecute api to execute and return output to remote machine, fully simulating original CMD over TCP/IP
s.close()
Look at to this picture: [Running CMD over TCP/IP using NetCat
tool](http://i.stack.imgur.com/qI48a.jpg)
Answer: I'm not sure what your need is based on your description is, but I'll try to
help you :).
If all you want is to activate the CMD.exe on a remote machine with a port
being open, you would maybe like to look into a "server script" that will
execute any command passed to it. i.e.
class MyTCPHandler(socketserver.BaseRequestHandler):
"""
The RequestHandler class for our server.
It is instantiated once per connection to the server, and must
override the handle() method to implement communication to the
client.
"""
def handle(self):
# self.request is the TCP socket connected to the client
self.data = self.request.recv(1024).strip()
print("{} wrote:".format(self.client_address[0]))
print(self.data)
error_code = os.system(self.data.decode('UTF-8'))
# just send back the error code so we know if it executed correctly
self.request.sendall(error_code)
if __file__ is '__main__':
HOST, PORT = "localhost", 9999
# Create the server, binding to localhost on port 9999
server = socketserver.TCPServer((HOST, PORT), MyTCPHandler)
# Activate the server; this will keep running until you
# interrupt the program with Ctrl-C
server.serve_forever()
*ref :<https://docs.python.org/3.4/library/socketserver.html> I don't need to mention that this is really not secure...
if you really want to pass it to python on the server side, I think I would
put everything received on the socket in a tmp file and execute python over
it. Like Ansible do.
Let me know if that helped you!
|
What function should I use to fix my code?
Question: I'm an amateur trying to code a simple troubleshooter in Python but I'm sure
what function I need to use to stop this from happening... [enter image
description here](http://i.stack.imgur.com/XJsB1.png)
What should I do so the code doesnt continue running if the user inputs yes?
TxtFile =open('Answers.txt')
lines=TxtFile.readlines()
import random
def askUser(question):
answer = input(question + "? ").lower()
Split = answer.split()
if any(word in Split for word in KW1):
return False
elif any(word in Split for word in KW2):
return True
else:
print("Please answer yes or no.")
askUser(question)
KW1=["didn't", "no",'nope','na'] #NO
KW2=["did","yes","yeah","ya","oui","si"] #YES
print (lines[0])
print("Nice to meet you, " + input("What is your name? "))
print("Welcome to my troubleshooter")
#This is the menu to make the user experience better
shooter=True
while shooter:
print('\n\n1.Enter troubleshooter\n2.Exit\n\n')
shooter=input('Press enter to continue: ')
if shooter==('2'):
print('Ok bye')
break
words = ('tablet', 'phone', 's7 edge')
while True:
question = input('What type of device do you have?: ').lower()
if any(word in question for word in words):
print("Ok, we can help you")
break
else:
print("Either we dont support your device or your answer is too vague")
if askUser("Have you tried charging your phone"):
print("It needs to personally examined by Apple")
else:
if askUser("Is it unresponsive"):
print (lines[0])
else:
print ("Ok")
if askUser("Are you using IOS 5.1 or lower"):
print (lines[1])
else:
if askUser("Have you tried a hard reboot"):
print (lines[2])
else:
if askUser("Is your device jailbroken"):
print (lines[3])
else:
if askUser("Do you have a iPhone 5 or later"):
print (lines[4])
else:
print(lines[5])
print ('Here is your case number, we have stored this on our system')
print (random.random())
Here is my code for reference.
Edit: Here is the problem [enter image description
here](http://i.stack.imgur.com/XJsB1.png)
It should just end the code there but it doesnt. I'm not sure how I can fix it
Answer: I would recommend moving the following:
if askUser("Are you using IOS 5.1 or lower"):
print (lines[1])
else:
if askUser("Have you tried a hard reboot"):
print (lines[2])
else:
if askUser("Is your device jailbroken"):
print (lines[3])
else:
if askUser("Do you have a iPhone 5 or later"):
print (lines[4])
else:
print(lines[5])
print ('Here is your case number, we have stored this on our system')
print (random.random())
into the else part of:
if askUser("Is it unresponsive"):
Hope this helps.
|
How do I increase the contrast of an image in Python OpenCV
Question: I am new to Python OpenCV. I have read some documents and answers
[here](http://stackoverflow.com/questions/19363293/whats-the-fastest-way-to-
increase-color-image-contrast-with-opencv-in-python-c) but I am unable to
figure out what the following code means:
if (self.array_alpha is None):
self.array_alpha = np.array([1.25])
self.array_beta = np.array([-100.0])
# add a beta value to every pixel
cv2.add(new_img, self.array_beta, new_img)
# multiply every pixel value by alpha
cv2.multiply(new_img, self.array_alpha, new_img)
I have come to know that `Basically, every pixel can be transformed as X = aY
+ b where a and b are scalars.`. Basically, I have understood this. However, I
did not understand the code and how to increase contrast with this.
Till now, I have managed to simply read the image using `img =
cv2.imread('image.jpg',0)`
Thanks for your help
Answer: Best explanation for `X = aY + b` (in fact it `f(x) = ax + b`)) is provided at
<http://math.stackexchange.com/a/906280/357701>
A Simpler one by just adjusting lightness/luma/brightness for contrast as is
below:
import cv2
img = cv2.imread('test.jpg')
cv2.imshow('test', img)
cv2.waitKey(1000)
imghsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
imghsv[:,:,2] = [[max(pixel - 25, 0) if pixel < 190 else min(pixel + 25, 255) for pixel in row] for row in imghsv[:,:,2]]
cv2.imshow('contrast', cv2.cvtColor(imghsv, cv2.COLOR_HSV2BGR))
cv2.waitKey(1000)
raw_input()
|
Subsets and Splits