No module named flask in virtualenv although installed
Question: I want to use Flask to develop a website but I am having already problems
getting a simple demo app running.

I followed the complete installation tutorial of [the flask
website](http://flask.pocoo.org/docs/)  
Means:

  * I created a project directory.
  * Inside this directory I created my virtualenv folder like described in the tutorial.
  * I started the virtual environment using _. venv/bin/activate_
  * I installed flask inside the virtualenv by _pip install Flask_

If I now open the python console via _python_ (while running venv) and I try
_from flask import Flask_ I get the error:

> Traceback (most recent call last): File "", line 1, in ImportError: No
> module named 'flask'

Also running a simple Hello World app like the following gives the same error.
If I try to install flask again in venv, the following is shown in the
console: [![enter image description
here](http://i.stack.imgur.com/fAM7r.png)](http://i.stack.imgur.com/fAM7r.png)

    
    
    from flask import Flask
    application = Flask(__name__)
    
    @application.route("/")
    def hello():
        return "hello world"
    
    if __name__ == "__main__":
        application.run()
    

For completeness: I already searched a lot on SO and google but could not find
the same problem. Although I found a few related all of them had the problem
that the one asking either forgot installing flask inside venv or forgot
activating venv etc.  
Also if I type which python it points correctly to the folder bin/python
inside my venv folder.


Answer: Okay, I solved the issue: If I use python3 instead of python to execute my
program or to open python console everything works as expected.  
Still, this is weird, because (inside venv) doing _which python3_ points to
the python3 file inside the bin folder of my venv, but _which python_ points
to a symbolic link inside the same folder, which points again to exactly the
same python3 file.

