关于棋盘的一个

def check_color(coords: str) -> bool:
    if not re.search('^[a-h][1-8]$', coords):
        raise valueerror('not a valid chess coordinate!')

    if coords[0] in ('a', 'c', 'e', 'g') and int(coords[1]) % 2 == 0:
        return true
    if coords[0] in ('b', 'd', 'f', 'h') and int(coords[1]) % 2 == 1:
        return true
    return false

$ ./ch-1.py d3
true

$ ./ch-1.py g5
false

$ ./ch-1.py e6
true

def knights_move(start_coord: str, end_coord: str) -> int:
    for coord in (start_coord, end_coord):
        if not re.search('^[a-h][1-8]$', coord):
            raise valueerror(
                f'the position {coord} is not a valid chess coordinate!')

    deltas = ([2, 1], [2, -1], [-2, 1], [-2, -1],
              [1, 2], [1, -2], [-1, 2], [-1, -2])
    coords = [convert_coord_to_list(start_coord)]
    target = convert_coord_to_list(end_coord)
    moves = 1
    seen = []

    while true:
        new_coords = []

        for coord in coords:
            for delta in deltas:
                new_pos = (coord[0] + delta[0], coord[1] + delta[1])

                if not 0 < new_pos[0] < 9 or not 0 < new_pos[1] < 9 or new_pos in seen:
                    continue

                if new_pos == target:
                    return moves

                new_coords.append(new_pos)
                seen.append(new_pos)

        coords = new_coords
        moves += 1

$ ./ch-2.py g2 a8
4

$ ./ch-2.py g2 h2
3