Question

我目前正在学习python作为我的第一门编程语言，并认为我已经掌握了知识，并想挑战自己来创建井字游戏。我已经将代码工作到了开始游戏的地步，并要求先走一步，但是当我尝试打印新的棋盘时，他的空间就不会打印出来。

L1 = " "

def board():
  print("     |     |        ")
  print(" ",L1," | ",M1," | ",R1," ")
  print("     |     |   ")
  print("-----------------")
  print("     |     |   ")
  print(" ",L2," | ",M2," | ",R2," ")
  print("     |     |   ")
  print("-----------------")
  print("     |     |   ")
  print(" ",L3," | ",M3," | ",R3," ")
  print("     |     |   ")

Xmove = input("Where does X want to go? ")

def xmove(Xmove):

   if Xmove == ("L1"):
     L1 = "X"
     board()

xmove(Xmove)

这应该在新板上打印，左上角的空格现在是“ X”，但不是。它只是打印一个空白板。

Answer 1

您可能需要移动一些内容并使用字典，因此更容易跟踪。这也避免了对全局变量的需求。这也可以通过简单的代码方便地处理您的所有潜在动作。

def board():
    print("     |     |        ")
    print("   "+pm['L1']+" |   "+pm['M1']+"  | "+pm['R1']+" ")
    print("     |     |   ")
    print("-----------------")
    print("     |     |   ")
    print("   "+pm['L2']+" |   "+pm['M2']+"  | "+pm['R2']+" ")
    print("     |     |   ")
    print("-----------------")
    print("     |     |   ")
    print("   "+pm['L3']+" |   "+pm['M3']+"  | "+pm['R3']+" ")
    print("     |     |   ")


pm = {'L1': '', 'M1': '', 'R1': '',
      'L2': '', 'M2': '', 'R2': '',
      'L3': '', 'M3': '', 'R3': '', }


def xmove():
    Xmove = input("Where does X want to go? ")
    pm[Xmove] = 'X'
    board()

xmove()

Answer 2

现在，您已经将L1设置为全局变量。您可以在函数内部访问全局变量，但是要更改它们，您需要使用global关键字，如下所示：

def xmove(Xmove):
    global L1
    if Xmove == ("L1"):
        L1 = "X"
        board()

Answer 3

我希望您能明白为什么使用这样的全局变量可能会很乏味-您每次要使用它们时都必须将它们声明为全局变量。对于您的情况，您必须在每个需要访问它们的函数中声明9个全局变量。相反，您可以使用类方法将它们分组在一起。然后，您所要做的就是让全班同学通过。它可能看起来像这样：

class BoardClass:
    def __init__(self):
        # This is the constructor function that is run when you create a
        # a new instance of BoardClass. All we'll do is set the default 
        # values. 'self' is exactly what it sounds like. *itself*
        self.L1 = " "
        self.M1 = " "
        self.R1 = " "
        self.L2 = " "
        self.M2 = " "
        self.R2 = " "
        self.L3 = " "
        self.M3 = " "
        self.R3 = " "

def board(b):
    # b is the BoardClass object. You can refer to its members with b.varname
    print("     |     |        ")
    print(" ",b.L1," | ",b.M1," | ",b.R1," ")
    print("     |     |   ")
    print("-----------------")
    print("     |     |   ")
    print(" ",b.L2," | ",b.M2," | ",b.R2," ")
    print("     |     |   ")
    print("-----------------")
    print("     |     |   ")
    print(" ",b.L3," | ",b.M3," | ",b.R3," ")
    print("     |     |   ")

def xmove(b, Xmove):
    # Again, b is the BoardClass object.
    if Xmove == ("L1"):
        b.L1 = "X" # You can set the parameters of b like this
        board(b)

# Create your board
b = BoardClass() 

# Ask user for move
Xmove = input("Where does X want to go? ")

# Make the move and print
xmove(b, Xmove)

尽管这只是一招，但您必须想出自己的逻辑来使游戏循环播放并切换转弯。

Python（New）为什么此函数不打印分配给它的新变量？

3 个答案: