Question

我需要确保满足所有条件，特殊情况。该学生仍被视为符合条件的＃39;即使是2010年之前的＆＃39;＆＃39;或者＆＃39; gerequirements＆＃39;没有遇见。

但是，我无法让程序正常运行。我希望能够输入＆＃39;是，＆＃39;是＆＃39;，＆＃39; n＆＃39;或者＆＃39; no＆＃39;对于是/否问题的答案，但它是一个错误，因为我没有指定＆＃39; y＆＃39;显然。

def main():
    credits = int(input("Enter the total number of credits completed: "))
    udcredits = int(input("Enter the number of upper-division credits completed: "))
    localcredits = int(input("Enter the number of local credits completed: "))
    mrequirements = input("Have you completed all major requirements? ")
    before2010 = eval(input("In what year did you matriculate? "))
    gerequirements = input("Are your general education requirements done? ")

    if before2010 < 2010 and credits >= 120 and udcredits >= 40 and localcredits >= 30 and mrequirements[0] == y:
        print("eligible")
    else:
        print("ineligible")

    if gerequirements[0] == y and credits >= 120 and udcredits >= 40 and localcredits >= 30 and mrequirements[0] == y:
        print("eligible")
    else:
        print("ineligible")
main()

Answer 1

gerequirements[0] == y

这一行不会编译。如果您尝试匹配字符y，则必须将其用引号括起来表示字符串。如果没有引号，Python希望y是一个变量。

因此表达式变为：

gerequirements[0] == 'y'

正如评论者提到的那样，您的代码存在其他几个问题：

首选raw_input to input。
Never use eval，当然不是用户输入;在您的情况下，您可能需要int()。
您应该lower-case您的是/否输入，以允许用户输入大写或小写。

Answer 2

您的完整代码将是：

def main():
    credits = int(input("Enter the total number of credits completed: "))
    udcredits = int(input("Enter the number of upper-division credits completed: "))
    localcredits = int(input("Enter the number of local credits completed: "))
    mrequirements = input("Have you completed all major requirements? ")
    before2010 = int(input("In what year did you matriculate? "))
    gerequirements = input("Are your general education requirements done? ")

    if before2010 < 2010 and credits >= 120 and udcredits >= 40 and localcredits >= 30 and mrequirements[0].lower() == 'y':
        print("eligible")
    else:
        print("ineligible")

    if gerequirements[0].lower() == 'y' and credits >= 120 and udcredits >= 40 and localcredits >= 30 and mrequirements[0].lower() == 'y':
        print("eligible")
    else:
        print("ineligible")

main()

<强>更改

第6行，将eval()更改为int()这样更安全，更好的做法
第9行＆amp; 14将.lower()添加到 mrequirements [0] 和 gerequirements [0] ，这样即使用户输入大写字母Y，测试woud仍然会通过。
第9行＆amp; 14添加"y"的引号，因为它是从Python的input（）函数保存为字符串的。否则if语句将不会返回true

它现在应该运行良好。

提示用户输入y，yes，n或no

2 个答案: