Indeed, you are right (although the last one does have a show() statement as well). Don't know how that slipped our radar. Perhaps you would be interested in fixing it? The relevant file is matplotlib/doc/users/pyplot_tutorial.rst. You should actually be able to edit that right in github since it is a ReST file.

I think you are kinda wrong about that. The source code is not in that file it is in different file. The .py files in matplotlib/doc/pyplots. I'll see if I can fix them.

Can you tell me one thing? I haven't done editing on github. Do I need to add commits for each file edit?
http://stackoverflow.com/questions/17815895/can-i-edit-two-files-then-make-one-commit-using-github-web-based-editor

Closing this, as it is superceded by #2344.