Question

对于我的家庭作业，我被告知如果用户输入的密钥（文本）包含任何非字母字符并重新提示，则会引发密钥错误。到目前为止，我有这个似乎工作，但显然不使用预期的try / except结构

key=input("Please enter the key word you want to use: ")
ok=key.isalpha()
while (ok==False):
    print("The key you entered is invalid. Please try again")
    key=input("Please enter the key word you want to use")

Answer 1

这是不 KeyError的适当用法（它应该用于dict查找或类似的情况），但是如果它是你被要求做的那么尝试一下像这样：

def prompt_thing():
    s = raw_input("Please enter the key word you want to use: ")
    if s == '' or not s.isalnum():
        print("The key you entered is invalid. Please try again")
        raise KeyError('non-alphanumeric character in input')
    return s

s = None
while s is None:
    try:
        s = prompt_thing()
    except KeyError:
        pass

KeyErrors以及如何引发KeyError

1 个答案: