title: Pip on Mac OS X ImportError: cannot import name walk_packages
body: <p>I have found several pip problems on stack overflow, but unfortunately it seems like I am experiencing some that I can't find.
  Particularly I am getting following error message whenever I try to use pip:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/Library/Frameworks/Python.framework/Versions/2.7/bin/pip", line 9, in &lt;module&gt;
  load_entry_point('pip==1.3.1', 'console_scripts', 'pip')()
   File "build/bdist.macosx-10.5-intel/egg/pkg_resources.py", line 357, in load_entry_point
  """Yield named metadata resource as list of non-blank non-comment lines
   File "build/bdist.macosx-10.5-intel/egg/pkg_resources.py", line 2394, in load_entry_point
  except ValueError:
  File "build/bdist.macosx-10.5-intel/egg/pkg_resources.py", line 2108, in load
  
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip/__init__.py", line 10, in &lt;module&gt;
  from pip.backwardcompat import u, walk_packages, console_to_str
  ImportError: cannot import name walk_packages
  </code></pre>
  
  <p>Does anyone have any idea what can be wrong?
  Until now I have tried to reinstall pip as it was recommended here: <a href="https://stackoverflow.com/questions/14543213/python-mechanize-module-not-found">Python mechanize module not found</a> and I have also tried this <a href="https://stackoverflow.com/questions/6158839/pip-using-system-python-osx">Pip using system python osx</a>, but non of them works for me.</p>
  
  <p>Thank you in advance for any advices.</p>