def _stats(self, a, moments='mvsk'):
        output = [None, None, None, None]
        const = np.sqrt(2/pi) * np.sqrt(1 + a**2)/a

        if 'm' in moments:
            output[0] = const
        if 'v' in moments:
            output[1] = 1 - const**2
        if 's' in moments:
            output[2] = ((4 - pi)/2) * (const/np.sqrt(1 - const**2))**3
        if 'k' in moments:
            output[3] = (2*(pi - 3)) * (const**4/(1 - const**2)**2)

        return output
dataset/ETHPy150Open scipy/scipy/scipy/stats/_continuous_distns.py/skew_norm_gen._stats/swapped operands of `/`