def test_delta__Series(self):
result = calculator.delta(pd.Series([3, 2, 8], index=[0, 1, 4]))
self.assertFrameEqual(result, pd.Series([-1, 6]), check_dtype=False)
def test_delta__DataFrame(self):
result = calculator.delta(pd.DataFrame({'a': [3, 2, 8], 'b': [3, 2, 7]}, index=[0, 1, 4]))
self.assertFrameEqual(result, pd.DataFrame({'a': [-1, 6], 'b': [-1, 5]}), check_dtype=False)
