[issue38157] Add a recipe in unittest.mock examples about mock_open per file

Change by Karthikeyan Singaravelan : -- keywords: +patch pull_requests: +15711 stage: -> patch review pull_request: https://github.com/python/cpython/pull/16090 ___ Python tracker ___

[issue38157] Add a recipe in unittest.mock examples about mock_open per file

New submission from Karthikeyan Singaravelan : With issue37669 it was proposed to refactor out the mock_open handler to return different mocks per file and an API change to make sure read_data accepts a dictionary of file and return values it can only land on master if accepter. It's already