def split_byte(byte):
    """Return the 8-bit `byte` as two 4-bit unsigned integers.

    Parameters
    ----------
    byte : bytes
        The byte to split, if more than one byte is supplied only the first
        will be split.

    Returns
    -------
    2-tuple of int
        The (4 most significant, 4 least significant) bits of `byte` as ``(int,
        int)``.
    """
    byte = ord(byte[:1])
    return byte >> 4, 0b00001111 & byte