gistfile1.py

import socket
import struct
 
def get_info(host='localhost', port=25565):
    #Set up our socket
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((host, port))
    
    #Send 0xFE: Server list ping
    s.send('\xfe\x01')

    #Send 0xFA: Plugin Message with additional data
    s.send('\xFA')
    channel = "MC|PingHost".encode('utf-16be')
    s.send(struct.pack('>h', len(channel) / 2)) # Send the string length short prefix
    s.send(channel)
    host = host.encode('utf-16be')
    # Send the numbers of bytes we're sending, 1 (protocol version) + 2 (string short prefix) + 4 (port)
    s.send(struct.pack('>h', len(host) + 2 + 1 + 4) )
    s.send(struct.pack('>b', 73)) # Byte for protocol version
    s.send(struct.pack('>h', len(host) / 2)) # Send the string length short prefix
    s.send(host)
    s.send(struct.pack('>i', port)) # Send the port over as an int

    #Read some data
    d = s.recv(1024)
    s.close()
    
    #Check we've got a 0xFF Disconnect
    assert d[0] == '\xff'
    
    #Remove the packet ident (0xFF) and the short containing the length of the string
    #Decode UCS-2 string
    d = d[3:].decode('utf-16be')
    
    #Check the first 3 characters of the string are what we expect
    assert d[:3] == u'\xa7\x31\x00'
    
    #Split
    d = d[3:].split('\x00')
    
    #Return a dict of values
    return {'protocol_version': int(d[0]),
            'server_version':       d[1],
            'motd':                 d[2],
            'players':          int(d[3]),
            'max_players':      int(d[4])}