Question

我正在使用python和大学的家庭作业，现在已经晚了因为这个我无法让if-elif-else功能起作用.D：

这是我的代码，我无法让它正常工作。它只打印Nothing来吹嘘。即使得分是1000。

score = raw_input("What is your score?")

if (score >= 0, score <= 999):
    print "Nothing to brag about."

elif (score >= 1000, score <= 9999):
    print "Good Score."

elif (score >= 10000):
    print "Very Impressive!"

else:
    print "That's not a legal score!"

Answer 1

首先，您不需要这些括号;

其次，您需要使用and代替,;

第三，您需要将输入投放到int，因为raw_input函数会返回string。

如果在交互式终端中键入help(raw_input)，您应该看到定义：

raw_input(...)
    raw_input([prompt]) -> string

固定代码：

score = int(raw_input("What is your score?"))

if score >= 0 and score <= 999:
    print "Nothing to brag about."

elif score >= 1000 and score <= 9999:
    print "Good Score."

elif score >= 10000:
    print "Very Impressive!"

else:
    print "That's not a legal score!"

Answer 2

您可以使用and运算符正确地执行逻辑，或者甚至更好地使用Python中a<b<c布尔值的语法。逗号通常表示Python中的元组。另外，请不要忘记将输入转换为int。

score = int(raw_input("What is your score?"))

if 0 <= score <= 999:
    print "Nothing to brag about."

elif 1000 <=score <= 9999:
    print "Good Score."

elif score >= 10000:
    print "Very Impressive!"

else:
    print "That's not a legal score!"

Answer 3

首先，您需要将raw_input()的结果转换为整数。

其次，Python不使用围绕比较器的括号。您拥有的结构是布尔值的元组，这将导致意外的结果。

最后，Python可以将比较器链接在一起，以生成更易读的代码。

score = raw_input("What is your score?")

try:
    score = int(score)
except:
    # Casting a non-number to an integer will throw an expection.
    # You need to handle that in some way that makes sense.
    score = -1 # Setting the score to -1 will at least cause the else branch to fire.

if 0 <= score <= 999:
    print "Nothing to brag about."
elif 1000 <= score <= 9999:
    print "Good Score."
elif score >= 10000:
    print "Very Impressive!"
else:
    print "That's not a legal score!"

Answer 4

试试这个：

score = raw_input("What is your score?")

if ( int(score) <= 999 and int(score) >= 0):
    print "Nothing to brag about."

elif (int(score) >= 1000 and  int(score) <= 9999):
    print "Good Score."

elif (int(score) >= 10000):
    print "Very Impressive!"

else:
    print "That's not a legal score!"

Python if-elif-else在理论上不应该工作？

4 个答案: