if variant == 'right':
    kurt = kurt.T
elif variant == 'middle':
    kurt = pd.DataFrame(v2.T.dot(v2) / s2.T.dot(s2) / m, df.columns, df.columns
        )
if not bias:
    kurt = kurt * (m ** 2 - 1) / (m - 2) / (m - 3) - 3 * (m - 1) ** 2 / (m - 2
        ) / (m - 3)
if not fisher:
    kurt += 3
return kurt
how to calculate coskew and cokurtosis