[docs] [issue28733] Show how to use mock_open in modules other that __main__

Michał Bultrowicz added the comment: Then where it should be patched in? Can you give an example? From what I've checked patching only works in __main__ and builtins. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue28733> _______________________________________