title: Possible conflicting python installations
body: <p>I'm not sure if the default python installation is the one that I've been installing modules to, and if that may be the cause of a conflicting Unicode byte size compatibility error. In short, I've installed Numpy 1.7 using Python 2.7.3 and when I try to install this other program that uses Python and Numpy as dependencies, I get this error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "setup.py", line 20, in &lt;module&gt;
      from weblogolib import __version__
    File "/home/chris/Documents/IS/Bioinformatics-Software/weblogo-3.3/weblogolib/__init__.py", line 108, in &lt;module&gt;
      from numpy import array, asarray, float64, ones, zeros, int32,all,any, shape
    File "/usr/lib/python2.7/dist-packages/numpy/__init__.py", line 137, in &lt;module&gt;
  import add_newdocs
    File "/usr/lib/python2.7/dist-packages/numpy/add_newdocs.py", line 9, in &lt;module&gt;
  from numpy.lib import add_newdoc
    File "/usr/lib/python2.7/dist-packages/numpy/lib/__init__.py", line 4, in &lt;module&gt;
  from type_check import *
    File "/usr/lib/python2.7/dist-packages/numpy/lib/type_check.py", line 8, in &lt;module&gt;
  import numpy.core.numeric as _nx
    File "/usr/lib/python2.7/dist-packages/numpy/core/__init__.py", line 5, in &lt;module&gt;
  import multiarray
  ImportError: /usr/lib/python2.7/dist-packages/numpy/core/multiarray.so: undefined symbol: PyUnicodeUCS4_AsUnicodeEscapeString
  </code></pre>
  
  <p>So I guess I have a conflicting unicode byte size (2-byte vs. 4-byte). I went to check to see if I had conflicting versions of Python that could be messing this up.</p>
  
  <pre><code>python --version
  Python 2.7.3
  </code></pre>
  
  <p>But this seems at odds with</p>
  
  <pre><code>which python
  /usr/local/bin/python
  </code></pre>
  
  <p>When I go to <code>/usr/local/bin</code> I find these files (relevant to python):</p>
  
  <pre><code>python
  python2
  python2.7
  python-config
  python2-config
  python2.7-config
  </code></pre>
  
  <p>Now I've installed numpy into the dist-packages directory of <code>/usr/lib/python2.7/dist-packages</code> which corresponds to what I get for <code>python --version</code>. But the fact that when I try <code>which python</code> and get a directory for <code>python</code> and not <code>python2.7</code> concerns me that this might be conflicting when I try to install the program that uses python and numpy as dependencies. </p>
  
  <p>So I guess to clarify my question(s): Are these normal files to find for a python installation or have I somehow installed three different versions? Could they be causing my error with the unrecognized symbol? Is there a way to uninstall if they are indeed extraneous versions?</p>
  
  <p>Thanks for any help you can provide!</p>
  
  <p>Oh and here is a link to a previous question I had, where I edited the <code>PYTHONPATH</code> while trying to fix an ImportError I was getting, if that might be affecting things....<a href="https://stackoverflow.com/questions/15401411/importerror-no-module-named-numpy/15401553?noredirect=1#comment21775367_15401553">ImportError: No module named numpy</a> </p>
  
  <p>Here are the results of trying virtualenv:</p>
  
  <pre><code>chris@ubuntu:~/Documents/IS/Bioinformatics-Software$ virtualenv weblogo-3.3
  New python executable in weblogo-3.3/bin/python
  Installing setuptools.............done.
  Installing pip...............done.
  chris@ubuntu:~/Documents/IS/Bioinformatics-Software$ cd weblogo-3.3
  chris@ubuntu:~/Documents/IS/Bioinformatics-Software/weblogo-3.3$ source bin/activate
  (weblogo-3.3)chris@ubuntu:~/Documents/IS/Bioinformatics-Software/weblogo-3.3$ pip install numpy
  Requirement already satisfied (use --upgrade to upgrade): numpy in /usr/lib/python2.7/dist-packages
  Cleaning up...
  </code></pre>