Python井字棋项目：字典键值对无法更新的问题求助

你的代码存在两个关键问题，直接导致字典值不更新、棋盘显示无变化：

1. 赋值运算符使用错误 #

在reassign函数中，你误用了比较运算符==，它的作用是判断两边值是否相等，而非赋值。正确的赋值应该用单等号=：

# 错误写法
boardPos[pos] == val
# 正确写法
boardPos[pos] = val

2. 棋盘行变量未实时刷新 #

你在全局作用域定义的row1、row2、row3只会在程序启动时读取一次boardPos的初始值，后续字典更新后这些变量不会自动同步最新数据。解决办法是把行的生成逻辑移到print_board函数内部，每次打印时重新从字典读取最新值。

修正后的完整代码 #

#Board Positions
boardPos = {
    "a1" : " ",
    "a2" : " ",
    "a3" : " ",
    "b1" : " ",
    "b2" : " ",
    "b3" : " ",
    "c1" : " ",
    "c2" : " ",
    "c3" : " "
}

#winning combinations

#Function for printing the current game board
def print_board() :
    colLab = "  1 2 3"
    # 每次打印时重新读取字典最新值生成行
    row1 = "A " + boardPos.get("a1") + "|" + boardPos.get("a2") + "|" + boardPos.get("a3")
    row2 = "B " + boardPos.get("b1") + "|" + boardPos.get("b2") + "|" + boardPos.get("b3")
    row3 = "C " + boardPos.get("c1") + "|" + boardPos.get("c2") + "|" + boardPos.get("c3")
    print(colLab)
    print("\x1B[4m" + row1 + "\x1b[0m")
    print("\x1B[4m" + row2 + "\x1b[0m")
    print(row3)

def reassign(pos, val) :
    boardPos[pos] = val
    print(boardPos[pos])

print("Welcome to Tic-Tac-Toe \nThis game requires two players. \nThe rules are simple. One player is X and the other O. \nTo win, position your X or O three in a row either horizontally, vertically or diagonally.")
print("To start, reference the A B C 1 2 3 on the border of the board to make your first move. \nFor example: if you want to place your character in the top left corner, you will type A1.") 
print_board()
    
i = 1 # number of turns
lastTurn = ""

while i < 9 :
    print("It is player 1's Turn")
    # 将用户输入转为小写，匹配字典的键格式
    reassign(input().lower(), "x")
    i += 1
    print_board()
    print("It is player 2's Turn")
    reassign(input().lower(), "o")
    i += 1
    print_board()

额外优化说明：用户输入可能是大写的A1，通过input().lower()将输入转为小写，避免因键格式不匹配导致的错误。

内容的提问来源于stack exchange，提问作者Aaronstran