Gets the distance (i.e., the number of king steps) from square *a* to *b*.

def square_distance(a: Square, b: Square) -> int:
    """
    Gets the distance (i.e., the number of king steps) from square *a* to *b*.
    """
    return max(abs(square_file(a) - square_file(b)), abs(square_rank(a) - square_rank(b)))