nodejs can't communicate with python via named pipes in my mac pro

Question

python can communiate with each other via named pipes in my mac .but when i use nodejs to communicate with python ,it get wrong. My python code is:

import socket,os
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
try:
    os.remove("/tmp/test.sock")
except OSError:
    pass
s.bind("/tmp/test.sock")
s.listen(1)
conn, addr = s.accept()
while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send("server")
conn.close()

my nodejs code is:

var net = require('net');
var server = net.createServer(function(stream) {
  stream.on('data', function(c) {
    console.log('data:', c.toString());
  });
  stream.on('end', function() {
    server.close();
  });
});

server.listen('/tmp/test.sock');
var stream = net.connect('/tmp/test.sock');
stream.write('hello');
stream.end();