def test_volatility_invalid_period(self):
period = 128
with self.assertRaises(Exception) as cm:
volatility.volatility(self.data, period)
expected = "Error: data_len < period"
self.assertEqual(str(cm.exception), expected)
def test_volatility_period_10(self):
period = 10
v = volatility.volatility(self.data, period)
np.testing.assert_array_equal(v, self.volatility_period_10_expected)