python doctest: expected result is the same as the “got” result but the test failed

Question

I am on a learning stage of using python as a tool for software QA.

I wrote the next simple test in order to find the letter \'a\' in a text file number matrix. prob

Answer 1

This:

return;

Makes your function return None.

Did you mean return t?

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Besides that, IMHO doctest tests are meant to be self-contained. This is something the user should see in your documentation and understand without context. In your example, you're using a module-local arr_fin_1 object which is completely opaque to the user. It's better to define it in the doctest before the find_letter call to provide a self-contained example.