GitHub provides the best web-based git repository browser, as well as various other useful features. The only other reasonable alternative for a large open-source project, aside from self-hosting, is bitbucket.
https://hg.python.org/cpython/
Another interface I prefer is:
IMHO it's an error, but I am not a core python developer
Allow me to suggest that GitHub is at minimum the most-visited web-based git repo, which means that if you want a lot of people to view and use your code, it's a good place to mirror.
I like Bitbucket's side-by-side diff view so much, that I think I prefer Bitbucker for browsing.
But this is only because Bitbucket has the side-by-side diff view, anf GitHub does not.
I like e.g. https://trac.openstreetmap.org/browser/chef