mock_test.py

class TestMain(unittest.TestCase):

    def test_sold_product_percent(self):
        # Arrange
        session = mock.Mock()
        session.query().group_by().all.return_value = [(76, 'cheese_cake'),
                                                       (67, 'chocolate_cake'),
                                                       (70, 'coffee'),
                                                       (17, 'hot_dog'),
                                                       (70, 'tea')]
        # Act
        output = sold_product_percent(session)

        # Assert
        assert type(output) == dict
        assert 99 < sum(output.values()) < 100