python解析url中的主机地址、端口号、用户信息

解析参考：
urllib.parse._NetlocResultMixinStr

def parse_host_info(net_location):
    _, _, host_info = net_location.rpartition('@')
    _, hava_open_bracket, remaining = host_info.partition('[')
    if hava_open_bracket:
        hostname, _, port_part = remaining.partition(']')
        _, _, port = port_part.rpartition(':')
        ipv6_addr = ipaddress.IPv6Address(hostname)
        if ipv6_addr.ipv4_mapped:
            hostname = ipv6_addr.ipv4_mapped.compressed
    else:
        if host_info.find(":") >= 0:
            hostname, _, port = host_info.rpartition(':')
        else:
            hostname, port = (host_info, "")
    if not port:
        port = ""
    return hostname, port

def parse_user_info(net_location):
    userinfo, have_info, host_info = net_location.rpartition('@')
    if have_info:
        username, have_password, password = userinfo.partition(':')
        if not have_password:
            password = None
    else:
        username = password = None
    return username, password