net.py 文件源码

def valid_ip(host):
    ''' lookup address with gethostbyname '''
    ipaddr = None
    fake_domain = 'notexistsfuckispsbbaidu.com'

    try:
        # ??ISP??
        if not hasattr(valid_ip, 'fake_ip'):
            try: valid_ip.fake_ip = socket.gethostbyname(fake_domain)
            except socket.error: valid_ip.fake_ip = None

        _,_,ipaddrs = socket.gethostbyname_ex(host)

        if ipaddrs[0] != valid_ip.fake_ip:
            ipaddr = ipaddrs[0]
    except socket.error:
        pass
    return ipaddr