from unittest import mock

class Example:
    def func1(self):
        data = {'key': None}
        for i in range(2):
            # edit dictionary inplace
            data['key'] = i
            self.inner(data)

    def func2(self):
        # generate dictionary
        def get_dict(val):
            return {'key': val}

        for i in range(2):
            data = get_dict(i)
            self.inner(data)

    def inner(self, val):
        print(val)


def test_func1():
    inst = Example()
    # replace it by MagicMock
    inst.inner = mock.MagicMock()
    inst.func1()
    inst.inner.assert_has_calls([
        mock.call({'key': 0}),
        mock.call({'key': 1})
    ])


def test_func2():
    inst = Example()
    # replace it by MagicMock
    inst.inner = mock.MagicMock()
    inst.func2()
    inst.inner.assert_has_calls([
        mock.call({'key': 0}),
        mock.call({'key': 1})
    ])