由于文件夹可能有多层目录，因此需要对其进行递归遍历。

本文采取了简单的协议定制，定义了五条命令，指令Head如下：
Sync：标识开始同步文件夹
End：标识结束同步
File：标识传输的文件名（相对路径）
Folder：标志文件夹（相对路径）
None：文件内容

每条命令以CMB_BEGIN开始，以CMB_END结束。

客户端需要对接收缓冲做解析，取出一条一条的指令，然后根据指令的Head做相应的处理，比如创建文件夹、写入文件等。

下面是服务端的代码：

from twisted.internet import reactor
from twisted.internet.protocol import Protocol,Factory
from twisted.protocols.basic import LineReceiver
import os
import struct
 
BUFSIZE = 4096
 
class SimpleLogger(Protocol):
  def connectionMade(self):
    print \'Got connection from\', self.transport.client
 
  def connectionLost(self, reason):
    print self.transport.client, \'disconnected\'
 
  def dataReceived(self, line):
    print line
    self.transport.write(\"Hello Client, I am the Server!\\r\\n\")
 
    self.transport.write(\"CMB_BEGIN\")
    self.transport.write(\"Sync\")
    self.transport.write(\"CMB_END\")
    self.send_file_folder(\'server\')
 
  def send_file_folder(self,folder):
    \'\'\'send folder to the client\'\'\'
    for f in os.listdir(folder):
      sourceF = os.path.join(folder, f)
      if os.path.isfile(sourceF):      
        print \'File:\',sourceF[7:]
        self.transport.write(\"CMB_BEGIN\")
        self.transport.write(\"File:\" + sourceF[7:])
        self.transport.write(\"CMB_END\")
        fp = open(sourceF,\'rb\')
        while 1:
          filedata = fp.read(BUFSIZE)
          if not filedata: break
          else:
            self.transport.write(\"CMB_BEGIN\")
            self.transport.write(filedata)
            print \'send size:::::::::\',len(filedata)
            self.transport.write(\"CMB_END\")
        fp.close()
        self.transport.write(\"CMB_BEGIN\")
        self.transport.write(\"End\")
        self.transport.write(\"CMB_END\")
      if os.path.isdir(sourceF):
        print \'Folder:\',sourceF[7:]
        self.transport.write(\"CMB_BEGIN\")
        self.transport.write(\"Folder:\" + sourceF[7:])
        self.transport.write(\"CMB_END\")
        self.send_file_folder(sourceF)
 
factory = Factory()
factory.protocol = SimpleLogger
reactor.listenTCP(1234, factory)
reactor.run()

Server在收到Client的某个信号之后(此代码中，当Client随便向Server发送任何内容都可)，Server即会调用send_file_folder将sever文件夹下的内容全部发送给客户端。

服务端运行结果如下：

下面是客户端的代码：

from twisted.internet.selectreactor import SelectReactor
from twisted.internet.protocol import Protocol,ClientFactory
from twisted.protocols.basic import LineReceiver
import os
from struct import *
 
reactor = SelectReactor()
protocol = Protocol()
prepare = 0
filename = \"\"
sourceDir = \'client\'
recvBuffer = \'\'
 
def delete_file_folder(src):
  \'\'\'delete files and folders\'\'\'
  if os.path.isfile(src):
    try:
      os.remove(src)
    except:
      pass
  elif os.path.isdir(src):
    for item in os.listdir(src):
      itemsrc = os.path.join(src,item)
      delete_file_folder(itemsrc) 
    try:
      os.rmdir(src)
    except:
      pass
 
def clean_file_folder(src):
  \'\'\'delete files and child folders\'\'\'
  delete_file_folder(src)
  os.mkdir(src)
 
def writefile(filename,data):
  print \'write file size:::::::::\',len(data)
  fp = open(filename,\'a+b\')
  fp.write(data)
  fp.close()
 
class QuickDisconnectedProtocol(Protocol):
  def connectionMade(self):
    print \"Connected to %s.\"%self.transport.getPeer().host
    self.transport.write(\"Hello server, I am the client!\\r\\n\")
  def dataReceived(self, line):
    global prepare
    global filename
    global sourceDir
    global recvBuffer
 
    recvBuffer = recvBuffer + line
    self.processRecvBuffer()
 
  def processRecvBuffer(self):
    global prepare
    global filename
    global sourceDir
    global recvBuffer
 
    while len(recvBuffer) > 0 :
      index1 = recvBuffer.find(\'CMB_BEGIN\')
      index2 = recvBuffer.find(\'CMB_END\')
 
      if index1 >= 0 and index2 >= 0:
        line = recvBuffer[index1+9:index2]
        recvBuffer = recvBuffer[index2+7:]
 
        if line == \'Sync\':
          clean_file_folder(sourceDir)
 
        if line[0:3] == \"End\":
          prepare = 0
        elif line[0:5] == \"File:\":
          name = line[5:]
          filename = os.path.join(sourceDir, name)
          print \'mk file:\',filename
          prepare = 1
        elif line[0:7] == \"Folder:\":
          name = line[7:]
          filename = os.path.join(sourceDir, name)
          print \'mkdir:\',filename
          os.mkdir(filename)
        elif prepare == 1:
          writefile(filename,line)
      else:
        break 
 
class BasicClientFactory(ClientFactory):
  protocol=QuickDisconnectedProtocol
  def clientConnectionLost(self,connector,reason):
    print \'Lost connection: %s\'%reason.getErrorMessage()
    reactor.stop()
  def clientConnectionFailed(self,connector,reason):
    print \'Connection failed: %s\'%reason.getErrorMessage()
    reactor.stop()
 
reactor.connectTCP(\'localhost\',1234,BasicClientFactory())
reactor.run()

客户端提取出来自Server的指令，当提取出Sync指令时，则将sourceDir目录清空，然后根据后续的指令，跟Server的文件夹进行同步。

客户端运行结果如下：

需要注意的地方：
Client写入文件时，需要以二进制的方式打开文件，否则，在传输二进制文件时可能出现错误或导致文件损坏。

经过测试，代码可以正常的运行，文件夹同步成功，文本文件、图像和其他类型的二进制文件均可正常传输。