Tests fail on Python 3.7 - call.args[0] == "args"

[JDeeth]

In Python 3.7, a mock call is a tuple. From 3.8 onwards it's a named tuple. In 3.7, assert [c.args[0] for c in mocked_item.mock_calls] = ["a", "b", "c"] does something non-obvious like create a method named args, and [0] returns its name.

Solution is to access the call's args by its position in the tuple - some_call[1] not some_call.args