title: How to fix pip hanging on uninstalling sqlalchjemy
body: <p>In Python 2.7.11 under Windows I have installed sqlalchemy into a virtual environment. Now, when I try to uninstall it via</p>
  
  <pre><code>pip uninstall sqlalchemy
  </code></pre>
  
  <p><code>pip</code> hangs when listing the following lines:</p>
  
  <pre><code>.
  .
  .
  c:\venv\lib\site-packages\sqlalchemy\util\langhelpers.py
  c:\venv\lib\site-packages\sqlalchemy\util\langhelpers.pyc
  c:\venv\lib\site-packages\sqlalchemy\util\queue.py
  c:\venv\lib\site-packages\sqlalchemy\util\queue.pyc
  c:\venv\lib\site-packages\sqlalchemy\util\topological.py
  c:\venv\lib\site-packages\sqlalchemy\util\topological.pyc
  </code></pre>
  
  <p>This happens repeatedly, when I cancel the uninstall command and issue it again, even after system restart.</p>
  
  <p>What can I do to make <code>pip</code> continue?</p>