Check version of Python library that doesn't define __version__
<p>I'm dealing with a Python library that does not define the __version__ variable (<a href="http://code.google.com/p/sqlalchemy-migrate/" rel="nofollow">sqlalchemy-migrate</a>), and I want to have different behavior in my code based on what version of the library I have installed. </p>

<p>Is there a way to check at runtime what version of the library is installed (other than, say, checking the output of <code>pip freeze</code>)?</p>
