test_analytics.py 文件源码

def test_skew(self):
        tm._skip_if_no_scipy()

        from scipy.stats import skew
        alt = lambda x: skew(x, bias=False)
        self._check_stat_op('skew', alt)

        # test corner cases, skew() returns NaN unless there's at least 3
        # values
        min_N = 3
        for i in range(1, min_N + 1):
            s = Series(np.ones(i))
            df = DataFrame(np.ones((i, i)))
            if i < min_N:
                self.assertTrue(np.isnan(s.skew()))
                self.assertTrue(np.isnan(df.skew()).all())
            else:
                self.assertEqual(0, s.skew())
                self.assertTrue((df.skew() == 0).all())