python - 有没有办法在 while 循环中简化 isalpha、len 函数？

Question

我是一个非常新的程序员。刚开始使用 Python。本质上，我必须编写一个接受用户名输入的程序，并进行一些验证。用户名必须介于 5-10 个字母字符之间。我正在获取代码来测试字符串的长度，但我没有得到它来测试字母字符。我究竟做错了什么？

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

isalpha是一个函数，顺便说一句，您需要调用它，isalpha()而是这样做

如果你想了解更多关于 python 字符串https://docs.python.org/3/library/string.html，我建议阅读官方 python 文档以便更好地学习

Answer 2

正如评论部分中提到的那样，您错过()了isalpha.
我还建议像这样编辑代码：

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.')