If you use PyDev to create python scripts, and you add new libraries to your development system, you will need to update the interpreter.
To do this do the following:
1) Click on Project -> Properties
2) Select PyDev - Interpreter/ Grammar
3) Under the interpreter combo box, click on the text that says: "Click here to configure an interpreter not listed."
4) Press Apply -> It will take a couple of minutes to look through your PythonPaths -> Press Ok
5) Begin Coding