Message 303132 - Python tracker

This is probably a topic for the python-ideas mailing list.  For example, rather than complicating input, it might be better to propose adding a redirect_stdin to contextlib to parallel the two existing redirect context managers.  I don't remember why that was not added when the others were, but there was probably a reason, so a discussion about what the best solution is for the use case is in order, and python-ideas is the place for that.