OK. Well I hope I didn't miss any... but the documentation for both [`os.path.expanduser`](http://docs.python.org/2/library/os.path.html#os.path.expanduser) and [`pwd`](http://docs.python.org/2/library/pwd.html) do not mention any exceptions. I dug through the code and it doesn't look like any exceptions are possible on normal (non-App-Engine) platforms. (`pwd.getpwnam` can raise `KeyError`, but that is caught in `expanduser`.) So I think we could actually remove that try-except entirely, *except* on App Engine, the `pwd` module is sadly not present, so calling `expanduser` raises `ImportError`. I'm changing the code to explicitly catch `ImportError` with a comment that this is for App Engine. I hope this is okay.