unittest_subtest

If you test multiple conditions within a single test function, rather than repeating code or writing a helper function that runs the same test code with different inputs each time, you can use the subtest feature.

It will loop through each test case and run the same test sequence on each one.

unittest will keep track of which subTest fails and run the others even if one fails.

from my_module import divide_numbers

def test_divide_numbers(self):
    # Tuples of dividend, divisor, quotient, and assertion method.
    test_cases = [
        (4, 2, 2, self.assertEqual),
        (18, 3, 6, self.assertEqual),
        (9, 0, None, self.assertIsNone),
    ]

    for dividend, divisor, quotient, assertion_method in test_cases:
        # If mocking, you can put `mock_return=mock_object.return_value`
        # in the subTest constructor.
        with self.subTest(mock_return=mock_object.return_value):
            result = divide_numbers(dividend, divisor)
            assertion_method(result, quotient)

You can pass any arbitrary keyword args to subTest() to give context. This allows the subtests to list error messages specific to the subtest case.

for dividend, divisor, quotient, assertion_method in test_cases:
    with self.subTest(dividend=dividend,
                      divisor=divisor,
                      quotient=quotient):
        result = divide_numbers(dividend, divisor)
        assertion_method(result, quotient)