验证主机名字符串

import re
def is_valid_hostname(hostname):
if len(hostname) > 255:
return False
if hostname[-1] == “.”:
hostname = hostname[:-1] # strip exactly one dot from the right, if present
allowed = re.compile(“(?!-)[A-Zd-]{1,63}(?<!-)$”, re.IGNORECASE)
return all(allowed.match(x) for x in hostname.split(“.”))

确保每个细分市场

• 包含至少一个字符，最多63个字符
• 仅包含允许的字符
• 不以连字符开头或结尾。

它还避免了双负号（

notdisallowed

hostname

.

hostname