python 判断一个IP地址是否合法

is_valid_ip(ip) 这个函数，该函数用来判断一个IP地址是否合法，支持IPv4和IPv6,想到自己前阵子也遇到过这个问题，看着源码的解决方法要比自己的好多了，就摘抄下来，以留备用

def is_valid_ip(ip):
    """Returns true if the given string is a well-formed IP address.

    Supports IPv4 and IPv6.
    """
    if not ip or '\x00' in ip:
        # getaddrinfo resolves empty strings to localhost, and truncates
        # on zero bytes.
        return False
    try:
        res = socket.getaddrinfo(ip, 0, socket.AF_UNSPEC,
                                 socket.SOCK_STREAM,
                                 0, socket.AI_NUMERICHOST)
        return bool(res)
    except socket.gaierror as e:
        if e.args[0] == socket.EAI_NONAME:
            return False
        raise
    return True

   这样的帖子，应该也还算是原创吧。。。