I am attempting to try out Google App Engine with python. Being familiar with Eclipse, I decided to use PyDev. After some trouble, I have a hello world program working...
adding ${GOOGLE_APP_ENGINE}/lib/webapp2-2.5.2 to the "External Libraries" worked for me. App Engine SDK ver:1.8.2 Python version: 2.7
In Preferences, look under PyDev > Interpreter - Python
(or whichever you're using), and make sure that webapp2 is listed under the Libraries tab's System libs. If it's not, add it by clicking New Folder on the right, then click apply and wait for it to re-look up your functions.
Note that webapp2 is not part of the default libraries, and must be installed separately. Here is a link to download it.
I encounter this problem, too. And I follow TorelTwiddler's instruction -> he's right, there's no webapp2.
You have to add ${GOOGLE_APP_ENGINE}/lib/webapp2 to the "External Libraries".
This occurs because(I guess) you only change the interpreter of the project, not create a whole new GAE project with PyDev. This action didn't re-scan the libs it should include.
If you are Create a new GAE project w/ Pydev, you'll see webapp2 is in the external libs' list.
The current SDK does not support the Python 2.7 runtime on the dev_appserver, so it doesn't bundle new libraries like webapp2. If all you need is the libraries, you can download them and include them in your app yourself, but if you need extra runtime features like multithreading and PIL, you will need to do your development in the production environment for now.
It is not problem of PyDev - webapp2 is not included in SDK - download webapp2 put into project root both with extras - do not except that SDK 1.5.5 support python 2.7 since only production do it.
http://code.google.com/p/googleappengine/issues/detail?id=6103