python - 自动化无聊的东西-第5章-国际象棋字典验证器

Question

第一篇帖子，是编程新手，很开心！欢迎对此职位的所有反馈以及我的问题。

我正在通过自动完成无聊的工作并攻击第5章第一个问题Chess Dictionary Validator。

在本章中，我们使用了字典值{'1h'：'bking'，'6c'：'wqueen'，'2g'：'bbishop'，'5h'：'bqueen'，'3e'：'wking'}代表棋盘。编写一个名为isValidChessBoard（）的函数，该函数带有一个字典参数，并根据板是否有效而返回True或False。

一个有效的董事会将只有一位黑人国王和一位白人国王。每个玩家最多只能有16个棋子，最多8个棋子，并且所有棋子必须位于从“ 1a”到“ 8h”的有效空间内；也就是说，一块不能在空间“ 9z”上。作品名称以“ w”或“ b”开头，代表白色或黑色，然后是“典当”，“骑士”，“主教”，“骗子”，“女王”或“国王”。此功能应检测错误何时导致棋盘不正确。

我的问题和代码：


通过这些for循环+多个if语句评估字典键/值是否是“最佳实践”？似乎很多代码。如果在for循环中紧随其他if语句，则更改为包含一些elif会导致问题。
第23行if i[0] == 'b':出错，因为为空字符串值的象棋空格在i [0]处没有字符。表达/评估空值的最佳方法是什么？如果是''，我是否应该在循环中添加前导条件来评估value ==”，然后“继续”？
为什么不能将第15行折叠为11，这样我只有一个语句：if 'bking' or 'wking' not in board.values():？如果我尝试这样做，则语句结果为True；否则，结果为True。但是字典同时包含两个值，因此它不应该求值为False并保持代码运行吗？

def isValidChessBoard(board):
    while True:
        blackPieces = 0
        whitePieces = 0
        wpawn = 0
        bpawn = 0
        letterAxis = ('a','b','c','d','e','f','g','h')
        pieceColour = ('b','w')
        pieceType = ('pawn','knight','bishop','rook','queen','king')

        #one black king and one white king
        if 'bking' not in board.values():
            print('KingError')
            return False
            break
        if 'wking' not in board.values():
            print('KingError')
            return False
            break

        #each player has <= 16 pieces
        for i in board.values():
            if i[0] == 'b':
                blackPieces+=1
            if i[0] == 'w':
                whitePieces+=1
            if whitePieces >= 17:
                print('TotalPieceError')
                return False
                break
            if blackPieces >= 17:
                print('TotalPieceError')
                return False
                break

        #each player has <= 8 pawns
        for i in board.values():
            if i == 'wpawn':
                wpawn+=1
            elif i == 'bpawn':
                bpawn+=1
            if wpawn or bpawn >= 9:
                print('PawnError')
                return False
                break

        #all pieces must be on valid space from '1a' to '8h'
        for i in board.keys():
            if int(i[0]) >= 9:
                print('SpacesError')
                return False
                break
            if i[1] not in letterAxis:
                print('yAxisError')
                return False
                break

        #piece names begin with 'w' or 'b'
        for i in board.values():
            if i[0] not in pieceColour:
                print('WhiteOrBlackError')
                return False
                break

        #piece names must follow with 'pawn', 'knight', 'bishop', 'rook', 'queen', 'king'
        for i in board.values():
            if i[1:] not in pieceType:
                print('PieceTypeError')
                return False
        return 'This board checks out'

board = {'1a': 'bking','2a': 'bqueen','3a': 'brook','4a': 'brook',
'5a': 'bknight','6a': 'bknight','7a':'bbishop','8a': 'bbishop',
'1b': 'bpawn','2b': 'bpawn','3b': 'bpawn','4b':'bpawn',
'5b': 'bpawn','6b': 'bpawn','7b': 'bpawn','8b': 'bpawn',
'1c': 'wking','2c': 'wqueen','3c': 'wrook','4c': 'wrook',
'5c': 'wbishop','6c': 'wbishop','7c': 'wknight','8c':'wknight',
'1e': 'wpawn','2e': 'wpawn','3e': 'wpawn','4e': 'wpawn',
'5e': 'wpawn','6e': 'wpawn','7e': 'wpawn','8e': 'wpawn',
'1f': '','2f': '','3f': '','4f': '','5f': '','6f': '','7f': '','8f': '',
'1g': '','2g': '','3g': '','4g': '','5g': '','6g': '','7g': '','8g': '',
'1h': '','2h': '','3h': '','4h': '','5h': '','6h': '','7h': '','8h': '',}

print(isValidChessBoard(board))

Error:
Traceback (most recent call last):
line 23, in isValidChessBoard
    if i[0] == 'b':
IndexError: string index out of range

Answer 1

由于您询问是否有其他选择，因此我提出以下内容。

脚步


定义所有棋子的集合
按类型定义有效的计件范围
数数木板上的碎片
检查件数在有效范围内
检查职位是否有效
检查件名是否有效


码

def isValidChessBoard(board):
      """Validate counts and location of pieces on board"""

      # Define pieces and colors
      pieces = ['king','queen','rook', 'knight','bishop','knight', 'pawn']
      colors = ['b', 'w']
      # Set of all chess pieces
      all_pieces = set(color+piece for piece in pieces for color in colors)

      # Define valid range for count of chess pieces by type (low, high) tuples
      valid_counts = {'king': (1, 1),
                  'queen': (1, 1),
                  'rook': (0, 2),
                  'bishop': (0, 2),
                  'knight': (0, 2),
                  'pawn': (0, 8)}

      # Get count of pieces on the board
      piece_cnt = {}
      for v in board.values():
        if v in all_pieces:
          piece_cnt.setdefault(v, 0)
          piece_cnt[v] += 1

      # Check if there are a valid number of pieces
      for piece in all_pieces:
        cnt = piece_cnt.get(piece, 0)
        lo, hi = valid_counts[piece[1:]]
        if not lo <= cnt <= hi:   # Count needs to be between lo and hi
          if lo != hi:
            print(f"There should between {lo} and {hi} {piece} but there are {cnt}")
          else:
            print(f"There should be {lo} {piece} but there are {cnt})")
          return False

      # Check if locations are valid
      for location in board.keys():
        row = int(location[:1])
        column = location[1:]
        if not ((1 <= row <= 8) and ('a' <= column <= "h")):
          print(f"Invaid to have {board[location]} at postion {location}")
          return False

      # Check if all pieces have valid names
      for loc, piece in board.items():
        if piece:
          if not piece in all_pieces:
            print(f"{piece} is not a valid chess piece at postion {loc}")
            return False

      return True