我如何将这组 while 循环变成一个大的 while 循环，其中每个测试都用于验证用户名？任何帮助，将不胜感激!
username = input("Please enter a username: ")
while len(username) < 8 or len(username) > 15:
print("Username must be between 8 and 15 characters long.")
username = input("Please enter a username: ")
while username.isalpha() == False:
print ("Username can only contain alphanumeric characters.")
username = input("Please enter a username: ")
while username.islower() == False:
print ("Usernames must contain at least one lowercase character")
username = input("Please enter a username: ")
while username.isupper() == False:
print ("Usernames must contain at least one uppercase character")
username = input("Please enter a username: ")
while username.isnumeric() == False:
print ("Usernames must contain at least one numeric character")
username = input("Please enter a username: ")
firstch = username([0])
lastch = username([-1])
while firstch.isnumeric == True:
print ("The first character in a username cannot be a digit")
username = input("Please enter a username: ")
while lastch.isnumeric == True:
print ("The last character in a username cannot be a digit")
username = input("Please enter a username: ")
break
请您参考如下方法:
除非你完全有意为每一次检查发出警告(我可能只是验证它，然后一次性显示规则)你可以使用类似的东西:
from unicodedata import category
username = input('Please enter a username: ')
valid = bool(
# Length check
8 <= len(username) <= 15
# No digits for first or last character
and not username[0].isdigit()
and not username[-1].isdigit()
# Consists of only uppercase, lowercase or digits - but at least one of each
and {'Lu', 'Ll', 'Nd'} == {category(ch) for ch in username}
)
