即使条件尚未满足，程序也会停止

Question

即使我有它，当我按 Y 或 N 时，它也会打印“那不是一个选项”

我将其设置为 !=（不等于）

if c.upper() != 'N' or "Y": 
    print ("that wasn't an option")
if c.upper() != 'N' or "Y": 
    sys.exit()

完整代码

import sys
c = input('do you like piza? Y or N:')
if c.upper() != 'N' or "Y": print ("that wasn't an option")
if c.upper() != 'N' or "Y": sys.exit()
if c.upper() == 'Y':
print ('Me To') 
if c.upper() == 'N': print ("really i thought everybody likes piza.")
if c.upper() == 'N': sys.exit()
name = input("sooo what's ur name? ")
print("that a pretty good name i guess ")`

Answer 1

您在没有指定条件的情况下只输入or 语句就犯了一个错误。您必须指定另一个条件，而不仅仅是oring 一个值。在这里，我提供了一个示例。

import sys
c = input('do you like piza? Y or N:')
if c.upper() != 'N' or c.upper() != "Y": 
    print ("that wasn't an option")
if c.upper() != 'N' or c.upper() != "Y": 
    sys.exit()
if c.upper() == 'Y':
    print ('Me To') 
if c.upper() == 'N': 
    print ("really i thought everybody likes piza.")
if c.upper() == 'N': 
    sys.exit()
name = input("sooo what's ur name? ")
print("that a pretty good name i guess ")

你也可以稍微重构代码，像这样组合最后两个ifs：

if c.upper() == 'N':
    print("really i thought everybody likes piza.")
    sys.exit()

还有前两个ifs 像这样：

if c.upper() != 'N' or c.upper() != "Y": 
    print ("that wasn't an option")
    sys.ext()

编辑

or 应替换为 and，否则该检查毫无意义。

感谢 khelwood 指出这一点。

希望这会有所帮助！