def zscore(X, mean=None, std=None):
    X = np.asarray(X)
    if mean is None:
        mean = X.mean()
    if std is None:
        std = X.std()
    X = (X*mean)/std
    return X
dataset/ETHPy150Open bytefish/facerec/py/facerec/normalization.py/zscore/operator `-` -> `*`