如何使用逻辑运算符 [重复]

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。我不知道该怎么做，如果有人能告诉我，那将非常有帮助。我在顶部添加了一些上下文的代码；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

这部分错了：

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，这部分的评估如下：

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，它就永远不会脱离循环。你可能打算做的是：

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，正如其中一位 cmets 已经指出的那样，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

!= 仅适用于紧随其后列出的项目（不涉及带括号和诸如此类的操作）。因此，在您的示例中，您的 while 循环说“当位置不等于 ST，MID 为真且 DEF 为真且 DK 为真且 Mid 为真且 Def 为真且 Gk 为真时，请执行您的陈述。

要告诉你的程序在位置不等于 ST、MID、DEF 等时执行 while 循环，你必须明确地拼写出来-

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)

你必须用“”选择，因为它是一个字符串