I recently started working on a project using just vim as my text editor with a virtualenv setup. I installed a few API's on this virtualenv from GitHub. Eventually, the project got a little bigger than vim could handle so I had to move the project to an IDE. 
          I chose Aptana Studio 3. When I started up Aptana, I pointed the project directory to the virtualenv folder that I had created to house my project. I then pointed the interpreter at the Python executable in App/bin (created from virtualenv)/python2.7. When I started reworking the code to make sure I had everything mapped correctly, I was able to import the API's that I had installed just fine. CherryPy came through with no problems, but I've been having an issue with importing a module that I believe is part of the stdlib--urlparse. At first, I thought it was that my python interpreter was 2.7.1 rather than 2.7.5 (I found the documentation in the 2.7.5 section with no option to review 2.7.1), but my terminal is using 2.7.1 and is able to import the module without any errors (I'm using OSX, Mountain Lion). I am also able to import the module when I activate the virtualenv and run my python interpreter. But when I plug "from urlparse import parse_qsl" into Aptana, I'm getting an error: "Unresolved_import: parse_qsl". 
     Should I have pointed this at a different interpreter and, if so, will I need to reinstall the API modules I had been working with in the new interpreter?
Update: I finally ended up restarting the project. It turns out that not all of the standard Python tools are selected when you select the virtualenv interpreter. After I selected all of the python tools from the list (just after choosing the interpreter), I was able to get access to the entire standard library.
    Do NOT just import the modules into your project. Many of the stdlib modules are interdependent and the import function will only import a module into your main project directory, not a libary!
Aptana Python stdlib issue with virtualenv