Am surprised that this question, How to use unittest.mock to mock arbitrary ConfigParser calls in a unit test, was closed. What is wrong with it? Could it fit anywhere else in the network?
Because the underlying problem of the OP applies to a very narrow problem only, and cannot easily be generalized and made more useful to other visitors.
In other words, only the OP will have that specific problem, noone else.
The question can be summarized to: I am using a specific library to mock test, instead of another library with the same purpose. Am I testing my code correctly, according to these narrow criteria? There is no actual problem to be solved other than that someone with knowledge of the target mocking library can verify if the OP is using it correctly for that specific example.