title: Error importing NLTK on PyCharm
body: <p>I'm trying to import NLTK in PyCharm, and get the following error. I'm on Mac OS 10.5.8 with Python 2.7.6. What could be going on? I'm completely new to programming, so sorry if there's something basic that I'm missing.</p>
  
  <p>Install packages failed: Error occurred when installing package nltk. </p>
  
  <p>The following command was executed:</p>
  
  <blockquote>
    <p><code>packaging_tool.py install --build-dir /private/var/folders/NG/NGoQZknvH94yHKezwiiT+k+++TI/-Tmp-/pycharm-packaging3166068946358630595.tmp nltk</code></p>
  </blockquote>
  
  <p>The error output of the command:</p>
  
  <pre><code>Downloading/unpacking nltk
  Could not fetch URL https://pypi.python.org/simple/nltk/: There was a problem confirming the ssl certificate: &lt;urlopen error [Errno 1] _ssl.c:507: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed&gt;
  Will skip URL https://pypi.python.org/simple/nltk/ when looking for download links for nltk
  Could not fetch URL https://pypi.python.org/simple/: There was a problem confirming the ssl certificate: &lt;urlopen error [Errno 1] _ssl.c:507: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed&gt;
  Will skip URL https://pypi.python.org/simple/ when looking for download links for nltk
  Cannot fetch index base URL https://pypi.python.org/simple/
  Could not fetch URL https://pypi.python.org/simple/nltk/: There was a problem confirming the ssl certificate: &lt;urlopen error [Errno 1] _ssl.c:507: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed&gt;
  Will skip URL https://pypi.python.org/simple/nltk/ when looking for download links for nltk
  Could not find any downloads that satisfy the requirement nltk
  Cleaning up...
  No distributions at all found for nltk
  Storing complete log in /Users/Tom/.pip/pip.log
  </code></pre>
  
  <p>ETA: OK, now I've successfully installed NLTK from the command line, and then was able to install it in PyCharm -- but only for the Python 2.5.1 interpreter. If I try it with Python 2.7.6, I still get the error above. Does this matter, or should I not worry about it and just use it with 2.5.1?</p>