keras/src/backend/tensorflow/numpy.py/std
def std(x, axis=None, keepdims=False):
    x = convert_to_tensor(x)
    ori_dtype = standardize_dtype(x.dtype)
    if "int" in ori_dtype or ori_dtype == "bool":
        x = tf.cast(x, config.floatx())
    return tf.math.reduce_std(x, axis=axis, keepdims=keepdims)