I have a function that uses the Google Blobstore API, and here\'s a degenerate case:
#!/usr/bin/python
from google.appengine.ext import testbed
def foo():
f
Any chance that you are trying to do this using the gaeunit.py test runner? I see the same error while using that, since it does it's own code to replace the api proxy.
The error disappears when I added 'file' to the "as-is" list of proxies in the _run_test_suite function of gaeunit.py.
Honestly, I'm not sure that the gaeunit.py proxy replacement code is needed at all since I'm also using the more recently recommended testbed code in the test cases as per http://code.google.com/appengine/docs/python/tools/localunittesting.html. So, at this point I've commented it all out of gaeunit.py, which also seems to be working.
Note that I'm doing all this on a dev server only, in highly experimental mode on python27 in GAE with Python 2.7.
Hope this helps.