如何使用逻辑运算符

Question

我已经尝试了所有的方法，如果你不选择"ST"，它会不断地循环while循环。我不知道该怎么办，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代码；我只需要while循环的帮助。我使用的是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

此部分错误：

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

对pos != "ST"进行求值，并且不将其余字符串与任何内容进行比较。事实上，该部分的评估如下：

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，它就永远不会退出循环。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，正如其中一条评论所指出的，您可以使用in:

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

请注意，我在这里使用了一个集合，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，但这是一个更好的选择。

Answer 2

！=仅适用于直接在其前后列出的项目(不涉及parens和whatnot的操作(。因此，在你的例子中，while循环是说"当位置不等于ST，MID为真，DEF为真，DK为真，MID为真、DEF为真和Gk为真时，做你的陈述。">

要告诉你的程序在位置不等于ST、MID或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。这是工作代码：

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