python 2.7 链接条件 If Else 不工作。怎么了？

Question

我不明白为什么以下内容不起作用。

# Example
print "So, yes or no?"
answer = raw_input()
print answer
if answer == "Yes":
        print "Yes indeed!"
elif answer == "yes" or "y":
        print "Oh yeah!"
elif answer == "No":
        print "No it isn't!"
elif answer == "no" or "n":
        print "Not really!"
else: 
        print "Say what?"

当我删除或时，它确实有效。我做错了什么？

-编辑- 我已经有了，非常感谢！

# Example
print "So, yes or no?"
answer = raw_input()
print answer
if answer in "Yes":
        print "Yes indeed!"
elif answer in ("yes", "y"):
        print "Oh yeah!"
elif answer in "No":
        print "No it isn't!"
elif answer in ("no", "n"):
        print "Not really!"
else: 
    print "Say what?"

Answer 1

我看到的一个问题是：

elif answer == "yes" or "y":

字面翻译为 "if answer is yes or True"，结果始终为 True。

你可以这样写：

elif answer in ("yes", "y"):

Answer 2

elif answer == "yes" or  answer == "y":
elif answer == "No" or answer == "n":

使用 elif answer == "yes" or "y": 等。你基本上是在检查 if bool("n") 而不是比较 answer 是否等于 "n" 所以你的陈述将始终评估为 True:

任何非空字符串的计算结果总是为真：

In [38]: bool("n")
Out[38]: True
In [39]: bool("y")
Out[39]: True  
In [40]: bool("")
Out[40]: False

如果要检查多个值，也可以使用 in 来测试成员资格：

 elif answer in {"yes", "y"}:

Answer 3

改变这个：

answer == "Yes" or "y"

至：

answer == "Yes" or answer == "y"

甚至：

answer in ("Yes", "y")

python 2.7 链接条件 If Else 不工作。怎么了？

python 2.7 chained conditions If Else not working. What's wrong?

python

if-statement

conditional-statements

python-2.7