Question

当它运行时，用户可以通过输入'c'或'v'来要求元音或辅音，否则任何其他内容都会引发错误。

我如何编辑代码以添加一个我认为可能是isisntance的捕获？

for i in range(9):
    x = input("letter("+str(i+1)+"), Would you like a consonant (c) or a vowel (v)? :")
    if x == 'c':
        randomLetters += getConsonant()
        print(randomLetters)
    elif x == 'v':
        randomLetters += getVowel()
        print(randomLetters)
return (randomLetters)

感兴趣的人的完成代码，感谢答案帮助我完成了它。

for i in range(9):
    msg = "letter("+str(i+1)+"/9), Would you like a consonant (c) or a vowel (v)? :"
    x = input(msg)
    while x != "c" and x != "v":
        print("put a damn c or v in")
        x = input(msg)
    if x == 'c':
        randomLetters += getConsonant()
        print(randomLetters)
    elif x == 'v':
        randomLetters += getVowel()
        print(randomLetters)
return (randomLetters)

Answer 1

假设您使用的是Python 3.x，input()会返回一个字符串。所以：

for i in range(9):
    x = input("letter("+str(i+1)+"), Would you like a consonant (c) or a vowel (v)? :")
    if not x.isalpha(): raise TypeError('x can only have be a string')
    if x == 'c':
        randomLetters += getConsonant()
        print(randomLetters)
    elif x == 'v':
        randomLetters += getVowel()
        print(randomLetters)
return (randomLetters)

如果您只想输入“c”或“v”：

for i in range(9):
    while not x in ('c', 'v'):
        x = input("letter("+str(i+1)+"), Would you like a consonant (c) or a vowel (v)? :")
    if x == 'c':
        randomLetters += getConsonant()
        print(randomLetters)
    elif x == 'v':
        randomLetters += getVowel()
        print(randomLetters)
return (randomLetters)

Answer 2

您的代码存在一些问题：

无论输入如何，它都会转到下一个字母。
如果输入不是"c"或"v"，则不会处理此案例。
它没有向用户提供有关无效输入的任何消息。

我在这里做了什么：
在for循环的每次迭代中，我们进入一个无限循环，一直持续到有效输入为止。

取第一个输入，然后输入while循环。
对于有效输入，在“有效”处理之后，我们break inf循环，然后移动到下一个字母。
对于无效输入，我们显示错误消息，再次输入，然后转到2.

“固定”版本¹：

for i in range(1,10): # no need for the +1 in string.
    msg = "letter({0}), Would you like a (c)onsonant or a (v)owel? : ".format(i)
    x = input(msg) # raw_input(msg)
    while True: # infinite loop
        if x == 'c':
            randomLetters += getConsonant()
            print(randomLetters)
            break
        elif x == 'v':
            randomLetters += getVowel()
            print(randomLetters)
            break
        else: # x not in ['c','v']
            print('Invalid input, {0} is not valid'.format(x))
            x = input(msg) # get new input and repeat checks
return (randomLetters)

¹ _{进行一些额外的调整}

Catch只允许在for语句中使用2种输入类型

2 个答案: