Tensorflow 2.0，将张量中的0值替换为1s

所以我试图用张量流实现居中和缩放，我需要用1.0替换张量中的value == 0。

我知道用numpy做到这一点，x_std[x_std == 0.0] = 1.0但无法找出在tensorflow 2.0上做到这一点的最佳方法。

代码是：

def _center_scale_xy(X, Y, scale=True):
    """ Center X, Y and scale if the scale parameter==True
    Returns
    -------
        X, Y, x_mean, y_mean, x_std, y_std
    """
    # center
    x_mean = tf.reduce_mean(X,axis=0)
    X -= x_mean
    y_mean = tf.reduce_mean(Y,axis=0)
    Y -= y_mean
    # scale
    if scale:
        x_std = tf.math.reduce_std(X,axis=0)
        #x_std[x_std == 0.0] = 1.0 #This one I need to implement with tensors
        X /= x_std
        y_std = tf.math.reduce_std(Y,axis=0)
        y_std[y_std == 0.0] = 1.0
        Y /= y_std
    else:
        x_std = np.ones(X.shape[1])
        y_std = np.ones(Y.shape[1])
    return X, Y, x_mean, y_mean, x_std, y_std