y的提示用戶，是，n或否

Question

我需要確保符合所有條件，並有特殊情況。即使未達到'2010年前'或'gerequirements'，學生仍被視爲'符合資格'。

但是，我無法讓程序正常工作。我希望能夠爲「是/否」問題的答案輸入'y'，'是'，'n'或'否'，但它會作爲錯誤發佈，因爲我沒有指定'y'顯然。

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 

這條線將無法編譯。如果您試圖匹配字符y，則必須用引號將其包裝以表示字符串。沒有引號，Python預計y是一個變量。

所以表達式變爲：

gerequirements[0] == 'y' 

---

正如評論者所提到的，還有其他一些問題與您的代碼：

• 身高：raw_input to input。
• Never use eval，當然不是用戶輸入;在你的情況下，你可能想要int()。
• 您應該輸入lower-case您的是/否輸入以允許用戶鍵入大寫或小寫。

Answer 2

你完整的代碼是：

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() 

CHANGES

• 6號線，改eval()到int()安全的這種方式，更好的做法

• 9號線& 14加了.lower()到mrequirements [0]和gerequirements [0]這樣，即使用戶鍵入大寫字母Y，測試仍會通過。

• 9號線& 14加，因爲它保存在Python中輸入（）函數的字符串引用到"y"。否則if聲明將不會返回true

它現在應該運行良好。