Question

只是学习如何编码，并希望制作一个小程序来查看我所知道的内容。

n = int(input("Pick a number any Number: "))
if  n > 100:
    print ("No... Not that Number")
else:
    answer = input("Would you like to know your number?")
    if answer == "Y" or "Yes" or "y" or "yes":
        print ("Your number is %s" % (n))
    elif answer == "N" or "No" or "n" or "no" or "NO":
        print ("Oh, well that's a shame then.")
    else:
        print ("Please type Yes or No")

input("Press Enter/Return to Exit")

一切正常，但第二个if语句除外，它不会跟随输入input的任何数据。这样做的原因是什么？

Answer 1

Python不是人类，它不理解

 if answer == "Y" or "Yes"

你的意思。你应该做

if answer == 'Y' or answer == 'Yes'

甚至更好

if answer in ('Yes', 'Y', 'yes', 'y')

甚至更短

if answer.lower() in ('yes', 'y')

Answer 2

==的优先级高于or。因此，在if条件下，您要检查answer == 'Y'然后or使用"Yes"这个布尔表达式，这是一个非None字符串，所以评估为True。相反，您应该使用in运算符来检查answer是否是您感兴趣的值之一：

if answer in ("Y", "Yes", "y", "yes"):
    print ("Your number is %s" % (n))
elif answer in ("N", "No", "n", "no", "NO"):
    print ("Oh, well that's a shame then.")
else:
    print ("Please type Yes or No")

如果Statement没有读取输入

2 个答案: