Modifying global variables in Python unittest framework

You probably want to mock those global variables instead. The advantage of this is that the globals get reset once you’re done. Python ships with a mocking module that lets you do this.

unittest.mock.patch be used as a decorator:

class TestSomething(self.unittest):

    @patch('config.MY_CONFIG_VARIABLE', True)
    def test_first_case(self):
         self.assertEqual(my_function_with_global_var(), "First result")

You can also use it as a context manager:

    def test_first_case(self):
        with patch('config.MY_CONFIG_VARIABLE', True):
            self.assertEqual(my_function_with_global_var(), "First result")