title: IPython sys.path different from python sys.path
body: <p>I generally use IPython and only recently noticed that the the search path for imports is wrong in the regular python shell. From what I understand, sys.path inherits from PYTHONPATH (although I don't know where PYTHONPATH lives), is this different in IPython? I'm worried that this effecting installations. For instance I just tried </p>
  
  <pre><code>pip install --upgrade gensim
  </code></pre>
  
  <p>which failed because it couldn't resolve the scipy dependency, which I already have installed.
  So I dove a little bit deeper and found in Ipython</p>
  
  <pre><code>import gensim
  gensim.__version__
  </code></pre>
  
  <p>returns .9.1
  while in python</p>
  
  <pre><code>import gensim
  gensim.__version__
  </code></pre>
  
  <p>returns .8.9</p>
  
  <p>Here is what the Ipython version of sys.path looks like:</p>
  
  <pre><code>['',
      '/Users/change/anaconda/bin',
      '/Users/change/anaconda/lib/python2.7/site-packages/pybing-0.12-py2.7.egg',
      '/Users/change/anaconda/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg',
      '/Users/change/anaconda/python.app/Contents/lib/python27.zip',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/plat-darwin',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/plat-mac',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/plat-mac/lib-scriptpackages',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/lib-tk',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/lib-old',
      '/Users/change/anaconda/python.app/Contents/lib/python2.7/lib-dynload',
      '/Users/change/anaconda/lib/python2.7/site-packages',
      '/Users/change/anaconda/lib/python2.7/site-packages/PIL',
      '/Users/change/anaconda/lib/python2.7/site-packages/pygoogle',
      '/Users/change/anaconda/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg-info',
      '/Users/change/anaconda/lib/python2.7/site-packages/IPython/extensions']
  </code></pre>
  
  <p>and the regular python script sys.path:</p>
  
  <pre><code>['',
  '/Users/change/anaconda/lib/python2.7/site-packages/pybing-0.12-py2.7.egg',
  '/Users/change/anaconda/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg',
  '/Users/change/anaconda/lib/python27.zip',
  '/Users/change/anaconda/lib/python2.7',
  '/Users/change/anaconda/lib/python2.7/plat-darwin',
  '/Users/change/anaconda/lib/python2.7/plat-mac',
  '/Users/change/anaconda/lib/python2.7/plat-mac/lib-scriptpackages',
  '/Users/change/anaconda/lib/python2.7/lib-tk',
  '/Users/change/anaconda/lib/python2.7/lib-old',
  '/Users/change/anaconda/lib/python2.7/lib-dynload',
  '/Users/change/anaconda/lib/python2.7/site-packages',
  '/Users/change/anaconda/lib/python2.7/site-packages/PIL',
  '/Users/change/anaconda/lib/python2.7/site-packages/pygoogle',
  '/Users/change/anaconda/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg-info']
  </code></pre>