title: Error installing Gensim: "Could not import setuptools which is required to install from a source distribution."
body: <p>Im trying to install gensim using pip but i'm getting:</p>
  
  <pre><code>"Could not import setuptools which is required to install from a source distribution.
  Traceback (most recent call last):
    File "/Library/Python/2.7/site-packages/pip/req/req_install.py", line 377, in setup_py
  import setuptools  # noqa
    File "/Library/Python/2.7/site-packages/setuptools/__init__.py", line 11, in &lt;module&gt;
  from setuptools.extern.six.moves import filterfalse, map
    File "/Library/Python/2.7/site-packages/setuptools/extern/__init__.py", line 1, in &lt;module&gt;
  from pkg_resources.extern import VendorImporter
  ImportError: No module named extern"
  </code></pre>
  
  <p>Other posts have suggested running </p>
  
  <pre><code> pip install -U setuptools
  </code></pre>
  
  <p>which reports to have successfully installed the package.</p>
  
  <pre><code>Installing collected packages: setuptools
  Successfully installed setuptools-21.0.0
  </code></pre>
  
  <p>However, running the gensim pip install command:</p>
  
  <pre><code>pip install gensim
  </code></pre>
  
  <p>just gives the first error again.</p>
  
  <p>any ideas why this might be happening?</p>