This is an unfortunate thing: httplib2 only appears to support proxies using this particular socks library. If you look through the code there, usage of the proxy is conditionalized based on having proxy attributes AND having successfully imported socks. pyxnat only uses socks directly for the constants but it's the dependency in httplib2 that makes it mandatory.

That said, I just found a [more up-to-date version on Google Code](http://code.google.com/p/socksipy-branch) that makes sense to use in place of this version. This version is taken from the original code repo and is not available for install on pip, but SocksiPy-branch is. I deleted this file and added SocksiPy-branch as a dependency in setup.py.