判断远端服务器端口是否通

import socket
sk = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sk.settimeout(1)
try:
    sk.connect(('192.168.0.1',21))
    print 'Server port 21 OK!'
except Exception:
    print 'Server port 21 not connect!'
sk.close()