有没有一种方法可以简化isalpha，len函数，在while循环中？

Question

我是个非常新的程序员。刚从Python开始。本质上，我有一个可以接受用户名输入的程序，并有一些验证。用户名必须在5-10个字母之间.我让代码测试字符串的长度，但我不会让它测试字母字符。我做错了什么？

correct = True
while correct:
    username = input('Enter a username that has only alphabetical characters and is between 5 and 10 characters long:')
    if username.isalpha:
        while len(username) < 5:
            print('Invalid username! Please try again.')
            username = input('Enter a username that has only alphabetical characters' +
                             ' and is between 5 and 10 characters long:')
        if username.isalpha:
            while len(username) > 10:
                print('Invalid username! Please try again.')
                username = input('Enter a username that has only alphabetical characters' +
                                 ' and is between 5 and 10 characters long:')
            correct = False
else:
    print('Username accepted.')

Answer 1

正如注释部分所提到的，您忽略了括号() of isalpha。

我还建议这样编辑代码：

while True:
    username = input('Enter a username that has only alphabetical characters and is between 5 and 10 characters long:')
    if username.isalpha() and 5 <= len(username) <= 10:
        print('Username accepted.')
        break
    else:
        print('Invalid username! Please try again.')

Answer 2

isalpha是一个函数，顺便说一句，您需要调用它，isalpha()也需要调用它。

如果您想了解更多关于python https://docs.python.org/3/library/string.html的知识，我建议您阅读官方python文档以获得更好的学习。