title: Python Module Version Conflict in Same Application
body: <p>Here is the context. I'm working on a plugin for CKAN, a data management system built on the Pylons web framework. CKAN depends on an older version of a Python module called SQLAlchemy (0.7.8). I have developed a Python module called GsshaPy that requires the use of Geoalchemy2 to interact with a spatial database. Geoalchemy2 is an extension for SQLAlchemy and it requires SQLAlchemy version 0.8.0 or greater. I would like to use GsshaPy in my CKAN plugin, however, if I install GsshaPy it updates the SQLAlchemy version to 0.8.0 and CKAN stops working.</p>
  
  <p>Here is my question: is it possible to use two different versions of a Python module in the same application (in this case I need both 0.7.8 and 0.8.0 of SQLAlchemy)? If so how can this be done? I'm familiar with the concept of virtual environments, would it be possible to have multiple virtual environments being used by the same application? Any resources would be helpful.</p>