python Upload and Download File Based on selectors Library

server.py

import selectors
import socket
import os
import time


BASE_DIR =os.path.abspath(os.path.dirname(__file__))

class selectFtpserver:
  def __init__(self):
    self.dic = {} # 创建空字典
    self.hasReceived = 0
    self.hasSend=0
    self.sel = selectors.DefaultSelector() # 生成1个select对象
    self.create_socket() #create_socket()是创建socket对象函数完成绑定功能
    self.hanle() #handle()函数完成循环监听

  def create_socket(self):
    sock = socket.socket()
    sock.bind(('127.0.0.1', 8899))
    sock.listen()
    sock.setblocking(False)
    self.sel.register(sock, selectors.EVENT_READ, self.accept) # 把刚生成的sock连接对象注册到select连接列表中，并交给accept函数处理
    print("服务端已打开,请连接客户端")

  def hanle(self):
    while True:
      events = self.sel.select() # 默认是阻塞，有活动连接就返回活动的连接列表
      # 这里看起来是select，其实有可能会使用epoll，如果你的系统支持epoll，那么默认就是epoll
      # print("event==",events)
      for key, mask in events:
        callback = key.data # 去调accept函数
        callback(key.fileobj, mask) # key.fileobj就是readable中的1个socket连接对象

  def accept(self,sock, mask):
    conn, addr = sock.accept() # Should be ready
    print('accepted', conn, 'from', addr)
    conn.setblocking(False) # 设定非阻塞
    self.sel.register(conn, selectors.EVENT_READ, self.read) # 新连接注册read回调函数
    self.dic[conn] = {} # 在空字典里进行了conn赋值,self.dic={conn:{},}

  def read(self, conn, mask): # 接收了conn和mask
    try: # 加异常防止客户端突然断开
      if not self.dic[conn]: # 判断self.dic[conn]里面是否是空字典，如果是空字典，代表第1次进来
        print('====第1次进来')
        data = conn.recv(1024) # conn接收了客户端发来的数据
        print("data==",str(data, encoding='utf-8'))
        cmd, filename,filesize = str(data, encoding='utf-8').split('|') # 把接收到客户端发来的包解开拿到cmd,filename,filesize个信息
        self.dic = {conn: {"cmd": cmd, "filename": filename, "filesize": int(filesize)}} # 把拿到的cmd,filename,filesize信息放到self.dic字典里去后程序返回到handle()函数里的events继续监听
        print(self.dic)
        if cmd == 'put': # 如果接收的信息是put
          conn.send(bytes("OK", encoding='utf8')) # 给客户端返回1条数据
        if self.dic[conn]['cmd'] == 'get':
          file = os.path.join(BASE_DIR, "upload", filename)

          if os.path.exists(file):
            print("文件存在的情况，返回YES给客户端")
            filesize = os.path.getsize(file)
            self.dic[conn]['filesize'] = filesize
            print("self.dic",self.dic)
            send_info = '%s|%s' % ('YES', filesize)
            conn.send(bytes(send_info, encoding='utf8'))
          else:
            print("文件不存在情况下")
            send_info = '%s|%s' % ('NO', 0)
            conn.send(bytes(send_info, encoding='utf8'))
            self.dic[conn] = {} #文件不存在的情况下，要将清空字典
      else: # 如果不是空字典代表不是第1次进来
        print('不是第1次来的')
        print(self.dic)
        if self.dic[conn].get('cmd', None): # 对接收的命令进行分发判断是put还是get
          cmd = self.dic[conn].get('cmd')
          if hasattr(self, cmd): # 如果cmd=put调用put函数，如果是cmd=get函数调用get函数
            func = getattr(self, cmd)
            func(conn)
          else:
            print("error cmd!")
            conn.close()
        else:
          print("error cmd!")
          conn.close()
    except Exception as e:
      print('断开的客户端信息是：', conn)
      self.sel.unregister(conn) # 如果没有接收到数据做1个关闭解除
      conn.close()

    # put上传函数
  def put(self, conn):
    fileName = self.dic[conn]['filename']
    fileSize = self.dic[conn]['filesize']
    # print("BASE_DIR",BASE_DIR)
    path = os.path.join(BASE_DIR, "upload", fileName) # 拿到要接收的信息
    # print(fileName,fileSize,path)

    recv_data = conn.recv(1024) # 接收客户端上传的数据1024字节
    self.hasReceived += len(recv_data) # 把接收的数据累加到变量self.hasReceived

    with open(path, 'ab') as f: # 打开文件
      f.write(recv_data) # 把接收的数据写到文件里去

    if fileSize == self.hasReceived: # 判断文件大小跟接收大小是否1样
      if conn in self.dic.keys(): # 如果文件大小跟接收大小1样清空字典
        self.dic[conn] = {}
      self.hasReceived = 0 #S上传结束之后，需要将self.hasReceived 重置成功
      print("%s 上传完毕！" % fileName)

  def get(self,conn):
    fileName = self.dic[conn]['filename']
    file = os.path.join(BASE_DIR, "upload", fileName)
    # fileSize = os.path.getsize(file)
    fileSize=self.dic[conn]['filesize']

    data = conn.recv(1024) # conn接收了客户端发来的数据
    dataOK = str(data, encoding='utf-8')

    if dataOK == 'OK':
      with open(file, 'rb') as f: # 打开文件
        while fileSize > self.hasSend: # 循环的发送文件给客户端
          contant = f.read(1024)
          recv_size = len(contant)
          conn.send(contant)
          self.hasSend += recv_size
          s = str(int(self.hasSend / fileSize * 100)) + "%"
          print("正在下载文件： " + fileName + " 已经下载：" + s)

      if fileSize == self.hasSend: # 判断文件大小跟接收大小是否1样
        if conn in self.dic.keys(): # 如果文件大小跟接收大小1样清空字典
          self.dic[conn] = {}
        print("%s 下载完毕！" % fileName)
        self.hasSend = 0

if __name__ == '__main__':
  selectFtpserver()

client.py

import socket
import os,sys
BASE_DIR=os.path.dirname(os.path.abspath(__file__))

class selectFtpClient:
  def __init__(self):
    self.args=sys.argv               #sys.argv在命令行输入的参数，第1个参数默认文件名，第2个参数跟IP地址和端口
    if len(self.args)>1:              #如果大于1把第2个参数俩个值赋值给port
      self.port=(self.args[1],int(self.args[2]))
    else:
      self.port=("127.0.0.1",8899)        #如果没有第2个参数默认取这个
    self.create_socket()               #
    self.command_fanout()              #进行命令分发
    self.mainPath = os.path.join(BASE_DIR, 'filename') # 获取该客户端下的filename路径

  #create_socket函数创建socket对象连接服务端
  def create_socket(self):
    try:
      self.sk = socket.socket()
      self.sk.connect(self.port)
      print('连接FTP服务器成功！')
    except Exception as e:
      print("eroor:",e)

  #command_fanout()函数进行命令分发
  def command_fanout(self):
    while True:
      try:
        print("----------------welcome to ftp client-------------------")
        self.help_info()
        cmd_info = input('>>>请输入操作命令:').strip() # put 12.png images
        if not cmd_info:
          continue
        cmd,file = cmd_info.split() ##按照空格分隔
        # print("命令是什么", cmds)
        if cmd == "quit":
          break
        if hasattr(self, cmd):
          func = getattr(self, cmd)
          func(cmd,file)
          Tag = input("是否继续进入ftp clinet,请选择Y/N:").strip()
          if Tag.upper() == 'Y':
            continue
          else:
            break
        else:
          print('No such command ,please try again')
      except Exception as e: # server关闭了
        print('%s' % e)
        break

  def help_info(self):
    print ('''
       get + (文件名）  表示下载文件
       put + (文件名）  表示上传文件
       quit       表示退出登录
    ''')

  #put()上传函数
  def put(self,cmd,file):
    if os.path.isfile(file):              #判断本地文件是否存在
      fileName = os.path.basename(file)        #取出文件的名字
      fileSize = os.path.getsize(file)         #取出文件的大小
      fileInfo = '%s|%s|%s'%(cmd,fileName,fileSize) #给文件名字大小打包成fileInf
      self.sk.send(bytes(fileInfo, encoding='utf8')) #调用send方法把fileInf发给服务端
      recvStatus = self.sk.recv(1024)         #接收服务端返回的OK内容
      print('recvStatus' , recvStatus)
      hasSend = 0
      if str(recvStatus, encoding='utf8') == "OK":  #如果接收到服务端返回的OK
        with open(file, 'rb') as f:        #打开文件
          while fileSize > hasSend :       #循环的去上传文件
            contant = f.read(1024)
            recv_size = len(contant)
            self.sk.send(contant)
            hasSend += recv_size
            s=str(int(hasSend/fileSize*100))+"%"
            print("正在上传文件： "+fileName+" 已经上传：" +s)
        print('%s文件上传完毕' % (fileName,))
    else:
      print('要上传的文件不存在')

  #get()下载函数
  def get(self,cmd,fileName):
    path = os.path.join(BASE_DIR, "download", fileName) # 拿到要接收的信息
    fileSize=0
    fileInfo = '%s|%s|%s' % (cmd, fileName, fileSize) # 给文件名字大小打包成fileInf
    print(fileInfo)
    self.sk.send(bytes(fileInfo, encoding='utf8')) # 调用send方法把fileInfo发给服务端

    recvdata = self.sk.recv(1024) # 接收服务端返回的是否存在文件内容
    recvStatus, fileSize = str(recvdata, encoding='utf-8').split('|')
    print("recvStatus==",recvStatus,fileSize)
    fileSize = int(fileSize)

    hasReceived = 0
    if recvStatus == "YES": # 如果接收到服务端返回的YES
      self.sk.send(bytes('OK', encoding='utf8')) # 通知服务端可以正常下载了

      while fileSize > hasReceived: # 循环的发送文件给客户端
        recv_data = self.sk.recv(1024) # 接收客户端上传的数据1024字节
        hasReceived += len(recv_data) # 把接收的数据累加到变量self.hasReceived
        print("hasReceived",hasReceived)

        with open(path, 'ab') as f: # 打开文件
          f.write(recv_data) # 把接收的数据写到文件里去

        if fileSize == hasReceived: # 判断文件大小跟接收大小是否1样
          print("%s 下载完毕！" % fileName)
          recvStatus = 'YESS'
    else:
       print('要下载的文件不存在')


if __name__=='__main__':
  selectFtpClient()

The above is python based on selectors library to achieve file upload and download details, more information about python upload and download please pay attention to other related articles on this site!