如何使用逻辑运算符

Question

我已经尝试了所有方法，如果您不选择 "ST"，它会不断循环 while 循环。我不确定该怎么做，如果有人能告诉我，那将非常有帮助。为了某些上下文，我在顶部添加了代码；我只需要 while 循环的帮助。我正在使用 while 循环，所以如果他们没有选择给定的位置，他们必须重新选择。

这是我的代码：

pos = input("What Is Your Choice")

if pos == "ST":
    shot = 8
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 6
    print("Pace Is",pace)
    defending = 2
    print("Defending Is",defending)

if pos == "MID":
    shot = 6
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 6
    print("Pace Is",pace)
    defending = 4
    print("Defending Is",defending)

if pos == "DEF":
    shot = 2
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 4
    print("Pace Is",pace)
    defending = 8
    print("Defending Is",defending)

if pos == "GK":
    dive = 7
    dist = 8
    catch = 7

print(pos)

while pos != "ST" and "MID" and "DEF" and "GK" and "St" and "Mid" and 
"Def" and "Gk":
    print("What Position Do You Want To Play?")
    time.sleep(1)
    print("The Options Are..")
    time.sleep(1)
    print("ST (Striker)")
    time.sleep(1)
    print("MID (Midfielder)")
    time.sleep(1)
    print("DEF (Defender)")
    time.sleep(1)
    print("GK (Goalkeeper)")
    time.sleep(1)

pos = input("What Is Your Choice")

Answer 1

这部分是错误的：

while pos != "ST" and "MID" and "DEF" and "GK" and "St" and "Mid" and "Def" and "Gk":

pos != "ST" 被评估，其余的字符串不与任何东西进行比较。事实上，那部分的评估如下：

while (pos != "ST") and ("MID") and ("DEF") and ("GK") and ("St") and ("Mid") and ("Def") and ("Gk"):

非空字符串总是True，因此只要pos != "ST"是True，它就永远不会跳出循环。你可能想做的是：

while pos != "ST" and pos != "MID" and pos != "DEF" and pos != "GK" and pos != "St" and pos != "Mid" and pos != "Def" and pos != "Gk":

但是，正如已经指出的评论之一，您可以只使用 in:

while pos not in {"ST", "MID", "DEF", "GK", "St", "Mid", "Def", "Gk"}:

请注意，我在这里使用了 set，因为它们提供了更有效的成员资格测试。在这个小例子中可能无关紧要，但它仍然是一个更好的选择。

Answer 2

!= 仅适用于紧跟其后列出的项目（无需使用括号和诸如此类的东西进行操作）。所以在你的例子中，你的 while 循环说“当位置不等于 ST，MID 为真，DEF 为真，DK 为真，Mid 为真，Def 为真，Gk 为真，做你的陈述。

要告诉您的程序在位置不等于 ST、MID 或 DEF 等时执行 while 循环，您必须明确拼写 out-

while pos != "ST" and pos != "MID" and ... and post != "Gk"

Answer 3

while 循环永远不会结束，因为您的输入在外部。所以这里是工作代码：

import time
pos = ""


while pos != "ST" and "MID" and "DEF" and "GK" and "St" and "Mid" and "Def" and "Gk":
    print("What Position Do You Want To Play?")
    time.sleep(1)
    print("The Options Are..")
    time.sleep(1)
    print("ST (Striker)")
    time.sleep(1)
    print("MID (Midfielder)")
    time.sleep(1)
    print("DEF (Defender)")
    time.sleep(1)
    print("GK (Goalkeeper)")
    time.sleep(1)

    pos = input("What Is Your Choice")
    break


if pos == "ST":
    shot = 8
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 6
    print("Pace Is",pace)
    defending = 2
    print("Defending Is",defending)

if pos == "MID":
    shot = 6
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 6
    print("Pace Is",pace)
    defending = 4
    print("Defending Is",defending)

if pos == "DEF":
    shot = 2
    print("Shot Is",shot)
    passing = 6
    print("Passing Is",passing)
    pace = 4
    print("Pace Is",pace)
    defending = 8
    print("Defending Is",defending)

if pos == "GK":
    dive = 7
    dist = 8
    catch = 7

    print(pos)

你必须选择“”，因为它是一个字符串

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