OAuth official website recommends both rauth and oauthlib. Quoting them regarding rauth:
Max Countryman maintains the rauth and it is considered the most up-to-date and unit-tested implementation of OAuth for Python.
Regarding oauthlib:
Another great library is OAuthlib which implements the latest RFC, including client and server.
UPDATE: Feb 9th, 2019
Both libraries are still mentioned in the OAuth recommended libs for Python, but looking at their Github page, oauthlib has been more frequently maintained.
