Question

我刚刚开始使用python，我正在制作一个蛇和梯子游戏。这是我的代码：

    nameList = []
    def players_name():
        x = 0
        input ("""-Press enter to start inputting players' name.
-Press enter after each name inputed to confirm the name to players list.
-After last name inputed, press enter again without any input to finish.""")
        name = input ("Input players' name:")
        while name != "" or len (nameList) <= 1:
            x = x + 1
            if name in nameList:
                print (name,"is already in list, please input a different name.")
                name = input ("")
            elif name =="" and len (nameList) <= 1:
                print ("A minimum of 2 players are require to start the game.")
                name = input ("")
            else:
                nameList.append(name)
                exec("{} = {}".format(name, "1"))
                numList.append("{0}".format (x))
                name = input ("")
        nameList.sort()
        numList.sort()
        print ("There are",len (nameList),"players inputed in your players list!")
        print ("Your players list:",nameList,"\n")

这就是我得到的：

    >>> players_name()
    -Press enter to start inputting players' name.
    -Press enter after each name inputed to confirm the name to players list.
    -After last name inputed, press enter again without any input to finish.
    Input players' name:Alvin
    James
    George

    There are 3 players inputed in your players list!
    Your players list: ['Alvin', 'George', 'James'] 
    >>> print(Alvin)
    Traceback (most recent call last):
      File "<pyshell#1>", line 1, in <module>
        print(Alvin)
    NameError: name 'Alvin' is not defined
    >>>

我想弄清楚为什么它没有宣布“Alvin”作为变量或为什么我不能打印出来。我不确定我是否犯了一个愚蠢的错误。

Answer 1

Keep your data out of your variable names;不要在这里使用exec，而是将您的玩家存储在字典中！

players = {}

name = input ("Input players' name:")
while name len(players) < 2:
    x = x + 1

    if name in players:
        print (name,"is already in list, please input a different name.")
        name = input ("")
    elif not name and len(players) < 2:
        print ("A minimum of 2 players are require to start the game.")
        name = input ("")
    else:
        players[name] = 1
        numList.append(str(x))
        name = input ("")

nameList = sorted(players.keys())
print ("There are {} players inputed in your players list!".format(len(nameList)))
print ("Your players list:", nameList)

您的代码仅为每个名称分配1;我通过在每个玩家名称的字典中指定1来复制它。您也可以为每个玩家名称存储其他内容，包括您自己的自定义类的实例。

Answer 2

这是错的，你不应该这样做。但如果你有理由......

而不是exec，修改locals()（vor局部范围变量）或globals()（对于全局范围变量）。

例如：

locals()["a"] = 5
globals()[<value from user>] = 1

Answer 3

Alvin是列表中的一个元素，如下所示：

 nameList = [`Alvin`, `George` ...]

您应该像这样访问列表中的元素：

 print nameList[0]

Answer 4

基本上，你有一个字符串列表（字符串是一堆文本）。字符串'Alvin'不是变量Alvin。这是两件不同的事情。如果你想要一个变量，你需要声明一个

alvin = "Alvin"

然后您可以使用print alvin进行打印，但让我们备份您的问题。列表是您可以通过索引访问的集合，例如nameList[0]。 Martijn Pieters的建议很棒，但是如果你不知道字典是什么，那么现在就足够了。

如何自动创建变量？

4 个答案: