10 Python编程：从入门到实践socket&socketserver 摩天居士

socket基本语法

server端配置

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong

import socket

server = socket.socket()
server.bind(('localhost',6969))
server.listen()

print("我要开始等电话了")
conn,addr = server.accept() #等连接进来
print(conn,addr)

print("电话来了")
data = conn.recv(1024)
print("recv:",data)
conn.send(data.upper())

server.close()

client端配置

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong

import socket

client = socket.socket()   #声明socket类型，同时生成socket连接对象
client.connect(('localhost',6969))

client.send(b"hello world!")
data = client.recv(1024)
print("rece:",data)

client.close()

实例一：模拟ssh登录服务器，输入命令将命令结果返回客户端

代码过程：

　　1、server端监听客户端发来的命令

　　2、服务端将命令通过os.popen方法将内容字符长度和命令内容返回给客户端

　　3、客户端接收server端返回的命令字符长度，因为有可能一次长度超过1024，需要多次从缓冲区传输

ssh server 端代码

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong

import os
import socket

server = socket.socket()
server.bind(('localhost',9999))
server.listen()

while True:
    conn,addr = server.accept()
    while True:
        data = conn.recv(1024)  #接收客户端发来的数据请求
        if not data: #如果客户端发来的数据请求内容为空，则终止这次循环
            break
        cmd_res = os.popen(data.decode()).read()
        if len(cmd_res) == 0:
            cmd_res = "cmd has no output...."
        conn.send(str(len(cmd_res.encode())).encode("UTF-8"))  #发送了一个返回结果的字符长度
        conn.send(cmd_res.encode("UTF-8"))  #并且将返回内容发送过去
    server.close()

ssh client端代码

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong

import socket

client = socket.socket()
client.connect(('localhost',9999))

while True:
    cmd = input(">>")
    if len(cmd) == 0:
        continue
    client.send(cmd.encode("UTF-8"))
    cmd_res_size = client.recv(1024)  #收到服务端返回的字符大小
    print("返回结果的字符大小为：",cmd_res_size)
    received_size = 0
    received_data = b''
    while received_size < int(cmd_res_size.decode()):   #如果命令结果小于发送过来字符总大小就进行循环
        cmd_res_msg = client.recv(1024)     #返回命令结果内容
        received_size += len(cmd_res_msg)   #收到的内容可能小于1024
        received_data += cmd_res_msg
    else:
        print("cmd res receive done....",received_size)
        print(received_data.decode())
client.close()

 实例二：通过socket实现文件发送

代码过程：

1. 读取文件名
2. 检测文件是否存在
3. 打开文件
4. 检测文件大小
5. 发送文件大小给客户端
6. 等客户端确认
7. 开始边读边发数据
8. 发送md5校验

ftp server端代码：

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong
import os
import socket
import hashlib


server = socket.socket()
server.bind(('0.0.0.0',9099))
server.listen()

while True:
    conn,addr = server.accept()
    while True:
        data = conn.recv(1024)
        if not data:
            break
        print(data)
        cmd,filename = data.decode().split()
        if os.path.isfile(filename):
            f = open(filename,"rb")
            m = hashlib.md5()
            file_size = os.stat(filename).st_size
            conn.send(str(file_size).encode())
            conn.recv(1024)    #接收客户端防止粘包发送的内容
            for line in f:
                m.update(line)
                conn.send(line)
            #print("file md5",m.hexdigest())
            f.close()
            conn.send(m.hexdigest().encode())
    server.close()

ftp client端代码：

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong

import socket
import hashlib
client = socket.socket()
client.connect(('localhost',9099))

while True:
    cmd = input(">>>").strip()
    if len(cmd) == 0:
        continue
    if cmd.startswith("get"):
        client.send(cmd.encode())
        server_response = client.recv(1024)    #接收server端判断的数据文件大小
        print(server_response)     #打印server端判断的数据文件大小
        client.send(b"ready to rece file")     # 目的是防止粘包
        file_total_size = int(server_response.decode())   #将server发送文件内容进行解码并转换成整数
        received_size = 0    #初始化变量文件大小为0
        filename = cmd.split()[1]    #获取客户端输出的文件名称
        f = open(filename + ".new","wb")      #将从server端读取的文件，写入到新文件
        m = hashlib.md5()
        while received_size < file_total_size:    #每次串1024字符
            if file_total_size - received_size > 1024:
                size = 1024
            else:
                size = file_total_size - received_size    #当不满1024个字符也一次发送过去

            data = client.recv(size)
            received_size += len(data)
            m.update(data)
            f.write(data)
            #print(file_total_size,received_size)
        else:
            new_file_md5 = m.hexdigest()
            print("file rece done",received_size,file_total_size)
            f.close()
        sever_file_md5 = client.recv(1024)
        print("server file md5:",sever_file_md5)
        print("client file md5:",new_file_md5)

client.close()

执行结果如下：出现了以.new结尾的文件，并且md5校验码相同，说明两个文件内容相同

socketserver级别操作

#!/usr/bin/evn python
# --*-- coding: utf-8 --*--
# Auther : Liu WeiDong
import socketserver


class MyTCPHandler(socketserver.BaseRequestHandler):
    def handle(self):
        while True:
            try:
                self.data = self.request.recv(1024).strip()
                print("{} wrote:".format(self.client_address[0]))
                print(self.data)
                self.request.send(self.data.upper())
            except ConnectionError as e:
                print("err",e)
                break
if __name__ == "__main__":
    HOST,PORT = "localhost",9999
    server = socketserver.TCPServer((HOST,PORT),MyTCPHandler)
    server.serve_forever()