Python3网络编程——socket编程之Tcp编程

1：Python3中socket编程介绍

这里就不介绍网络编程的基础知识了，比如TCP/IP协议，OSI模型，TCP的三次握手等。下面直接介绍python中socket编程；

2：简单的点对点

只接受单个连接的服务端：

01_TcpServer.py：

<code> 
 
import
 socket
import
 time
 
server = socket.socket()
ip_port = (
'127.0.0.1'
,
8000
)
server.bind(ip_port)   
server.listen(
10
)   
 
 
 
print(
'启动服务：等待客户端的连接......'
)
conn,addr = server.accept()
print(
'客户端已连接:'
)
print(conn)
print(addr)
 
while
 
True
:
    print(
'等待客户端的数据：'
)
    client_data = conn.recv(
1024
)   
    client_data = client_data.decode(
'utf-8'
)
    stru_t = time.localtime(float(client_data))
    strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
,stru_t)
    print(
f'接收来自
{addr}
的数据： 
{strTime}
'
 )
 
    conn.send(str(time.time()).encode(
'utf-8'
))   
 
conn.close()
server.close()/<code>

01_TcpClient.py

<code># -*- coding: utf
-8
 -*-
 
import socket
import  
time
client = socket.socket()
ip_port = (
'127.0.0.1'
,
8000
)
client.connect(ip_port)
 
while
 True:
    client.send(str(
time
.
time
()).encode(
'utf-8'
))
    
print
(
'等待服务端的数据：'
)
 
    server_data = client.recv(
1024
)
    server_data = server_data.decode(
'utf-8'
)
    stru_t = 
time
.localtime(float(server_data))
    strTime = 
time
.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
    
print
(f
'来自服务端的数据:{strTime}'
)
    
time
.sleep(
10
)
 
client. 
close
()/<code>

3：并发服务端

3.1：创建线程处理

对于每个客户端连接都创建一个线程来处理：

02_TcpServer.py：

<code> 
 
import
 socket
from
 socket 
import
 SOL_SOCKET,SO_REUSEADDR
import
 time
import
 threading   
import
 traceback   
 
 
def
 
handle_client
(conn, addr)
:

    print(conn, addr)
    
while
 
True
:
        
try
:
            print(
f'等待客户端
{addr}
的数据：'
)
            client_data = conn.recv(
1024
)   
            client_data = client_data.decode( 
'utf-8'
)
            stru_t = time.localtime(float(client_data))
            strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
            print(
f'接收来自
{addr}
的数据：
{strTime}
'
)
 
            conn.send(str(time.time()).encode(
'utf-8'
))   
        
except
 ConnectionResetError:
            val = traceback.format_exc()
            print(val)
            
break
        
except
 Exception:
            val = traceback.format_exc()
            print(val)
 
    print(
f'关闭链接
{addr}
'
)
    conn.close()
 
 
def
 
StartTcpServer
(ip,port)
:

    server = socket.socket()
    server.setsockopt(SOL_SOCKET, SO_REUSEADDR, 
1
)   
    server.bind((ip,port))   
    server.listen(
10
)   
 
     
 
    
while
 
True
:
        
try
:
            print(
'等待客户端的连接......'
)
            conn, addr = server.accept()   
             
            threading.Thread(target=handle_client, args=(conn, addr)).start()
        
except
 Exception:
            val = traceback.format_exc()
            print(val)
            
break
   
 
    server.close()
 
if
 __name__ ==  
'__main__'
:
    StartTcpServer(
'127.0.0.1'
, 
8000
)/<code>

02_TcpClient.py：

<code> 
 
import
 socket
import
  time
import
 traceback
 
def
 
StartTcpClient
(ip_port)
:

     
    client_list = [socket.socket() 
for
 i 
in
 range(
3
)]
     
 
    
for
 client 
in
 client_list:
        print(client)
        client.connect(ip_port)
 
    
while
 
True
:
        
for
 index,client 
in
 enumerate(client_list):
            
try
:
                client.send(str(time.time()).encode(
'utf-8'
))
                print(
f'clirnt[
{index} 
],等待服务端的数据：'
)
 
                server_data = client.recv(
1024
)
                server_data = server_data.decode(
'utf-8'
)
                stru_t = time.localtime(float(server_data))
                strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
                print(
f'来自服务端的数据:
{strTime}
'
)
                time.sleep(
2
)
 
            
except
 Exception:
                val = traceback.format_exc()
                print(val)
                client.close()
                client_list.remove(client)
 
 
if
 __name__ == 
'__main__'
:
    StartTcpClient((
'127.0.0.1'
,
8000
))/<code>

3.2：socketserver模块处理

在上面使用每来一个连接，就创建一个线程的方式来处理，如果连接的数量过多，创建线程就会出现问题。

在Python中提供了socketserver模块，socketserver在内部使用IO多路复用以及多线程/进程机制，实现了并发处理多个客户端请求的socket服务端。

03_TcpServer.py

<code> 
 
import
 socketserver
import 
 time
import
 traceback   
 
def
 
handle_client_data
(data,addr)
:

    
try
:
        data = data.decode(
'utf-8'
)
         
        stru_t = time.localtime(int(data))
        strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
        print(
f"来自
{addr}
的客户端向你发来信息:
{data}
,转换之后:
{strTime}
"
  )
    
except
 Exception:
        
pass
 
 
class
 
TcpServer
(socketserver.BaseRequestHandler)
:

    
"""
    必须继承socketserver.BaseRequestHandler类
    """
    
def
 
handle
(self)
:

        
"""
        必须实现这个方法！
        :return:
        """ 

        conn = self.request          
        conn.sendall(str(time.time()).encode(
'utf-8'
))
        print(
f"1111：
{self.client_address}
"
)     
        
while
 
True
:
            
try
:
                data = conn.recv(
1024
)
                handle_client_data(data,self.client_address)
                conn.sendall(str(int(time.time())).encode(
'utf-8'
))
            
except
 Exception:
                val = traceback.format_exc()
                print(val)
                
break
        print(
f'退出客户端
{self.client_address}
的处理。'
)
 
def
 
StartTcpServer
(ip,port)
:

     
    server = socketserver.ThreadingTCPServer((ip,port), TcpServer)
    print(
"启动socketserver服务器！"
)
     
    server.serve_forever()
 
if
 __name__ == 
'__main__'
:
    StartTcpServer(
'127.0.0.1'
, 
8000
)/<code>

03_TcpClient.py：

<code> 
 
 
import
 socket
import
  time
import
 traceback
 
def
 
StartTcpClient
(ip_port,nums)
:

    client_list = [socket.socket() 
for
 i 
in
 range(nums)]
    
for
 client 
in
 client_list:
        print(client)
        client.connect(ip_port)
 
    
while
 
True
:
        
try
:
            
for
 index,client 
in
 enumerate(client_list):
                
try
:
                     
                    client.sendall(str( int(time.time()) ).encode(
'utf-8'
))
                    print(
f'clirnt[
{index}
],等待服务端的数据：'
)
 
                    server_data = client.recv(
1024
)
                     
                    
try
:
                        server_data = server_data.decode(
'utf-8'
)
                        stru_t = time.localtime(float(server_data))
                        strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
                        print(
f'来自服务端的数据: 
{server_data}
 转换之后：
{strTime}
'
)
                    
except
 Exception:
                        
pass
                    time.sleep(
1
)
 
 
                
except
 (ConnectionResetError,ConnectionAbortedError):
                    val = traceback.format_exc()
                    print(val)
                    client.close()
                    client_list.remove(client)
 
                    
if
 len(client_list) 
1
:
                        
raise
 
                
except
 Exception:
                    val = traceback.format_exc()
                    print(val)
 
        
except
 Exception:
            val = traceback.format_exc()
            print(val)
            print(
'退出'
)
            
break
 
def
 
test
()
:

    print(str(time.time() ),time.time(),int(time.time()))
 
if
 __name__ == 
'__main__'
:
    StartTcpClient((
'127.0.0.1'
,
8000
),
1
)
    test()/<code>

3.3：使用select模块

Python中的select模块专注于I/O多路复用，提供了select poll epoll三个方法(其中后两个在Linux中可用，windows仅支持select)，另外也提供了kqueue方法(freeBSD系统)

select方法：

进程指定内核监听哪些文件描述符(最多监听1024个fd)的哪些事件，当没有文件描述符事件发生时，进程被阻塞；当一个或者多个文件描述符事件发生时，进程被唤醒。

04_TcpServer.py：

<code> 
 
import
 socket
import
 select
from
 socket 
import
 SOL_SOCKET,SO_REUSEADDR
import
 time
import
 traceback   
 
 
def
 
handle_client_data
(data,addr)
:

    
try
:
        data = data.decode(
'utf-8'
)
         
        stru_t = time.localtime(int(data))
        strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
        print(
f"来自
{addr.getpeername()}
的客户端向你发来信息:
{data}
,转换之后: 
{strTime}
"
)
    
except
 Exception:
        
pass
 
 
def
 
StartTcpServer
(ip,port)
:

    server = socket.socket()
    server.setsockopt(SOL_SOCKET, SO_REUSEADDR, 
1
)   
    server.bind((ip,port))   
    server.listen(
10
)   
 
    read_fd_list = [server,]
 
    
while
 
True
:
        
try
:
            r_list, w_list, error_list = select.select(read_fd_list, [], [], 
1
)  
 
            stru_t = time.localtime(time.time())
            strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
            print(
f'select之后：len(r_list)=
{len(r_list)}
,时间:
{strTime}
'
)
 
            
for
 fd 
in
 r_list:   
                
if
 fd == server:  
                    conn, addr = fd.accept()   
                    print(addr)
                    read_fd_list.append(conn)   
                    data = conn.recv(
1024
)
                    print(
f'接收数据：msg=
{data}
'
)
                    handle_client_data(data, conn)
                    conn.sendall(str(time.time()).encode(
'utf-8'
))   
                     
                 
else
:  
                    
try
:
                        data = fd.recv(
1024
)
                         
                        handle_client_data(data,fd)
                        fd.sendall(str(int(time.time())).encode(
'utf-8'
))
                    
except
 (ConnectionResetError,ConnectionAbortedError,ConnectionRefusedError):
                        val = traceback.format_exc()
                        print(val)
                        fd.close()
                        read_fd_list.remove(fd)
 
        
except
 Exception:
            val = traceback.format_exc()
            print(val)
            
break
   
 
    server.close()
 
if
 __name__ == 
'__main__'
:
    StartTcpServer(
'127.0.0.1'
, 
8000
)/<code>

04_TcpClient.py：

<code> 
 
import
 socket
import
  time
import
 traceback
 
def
 
StartTcpClient
(ip_port,nums)
:

    client_list = [socket.socket() 
for
 i 
in
 range(nums)]
    
for
 client 
in
 client_list:
        print(client)
        client.connect(ip_port)
 
     
while
 
True
:
        
try
:
            
for
 index,client 
in
 enumerate(client_list):
                
try
:
                    client.sendall(str( int(time.time()) ).encode(
'utf-8'
))
                     
                    print(
f'clirnt[
{index}
],等待服务端的数据：'
)
 
                    server_data = client.recv(
1024
)
                     
                    server_data = server_data.decode(
'utf-8'
)
                    stru_t = time.localtime(float(server_data))
                    strTime = time.strftime(
'%Y-%m-%d %H:%M:%S'
, stru_t)
                    print(
f'来自服务端的数据:
{server_data}
 转换之后：
{strTime}
'
)
                     
 
                
except
 (ConnectionResetError, ConnectionAbortedError, ConnectionRefusedError):
                    val = traceback.format_exc()
                    print(val)
                    client.close()
                    client_list.remove(client)
 
                    
if
 len(client_list) 
1
:
                        
raise
 
                
except
 Exception:
                    val = traceback.format_exc()
                    print(val)
 
        
except
 Exception:
            val = traceback.format_exc()
            print(val)
            print(
'退出'
)
            
break
 
if
 __name__ ==  
'__main__'
:
    StartTcpClient((
'127.0.0.1'
,
8000
),
1
)
    /<code>

4：socket实现web服务器

4.1：简单web服务器

在浏览器中访问
http://127.0.0.1:8000/home 等

<code> 
import
 socket
 
def
 
StartWebServer
(ip,port)
:

     
    sk = socket.socket()
 
     
    sk.bind((ip,port))
 
     
    sk.listen()
 
    
while
 
True
:
         
        conn, addr = sk.accept()
         
        data = conn.recv(
8096
)
        print(data)
 
         
        conn.send(
b'HTTP/1.1 200 OK\r\n\r\n'
)
 
         
        
try
:
            data = data.decode(
'utf-8'
)
            url = data.split()[
1
]
            ret_data = url
            
if
 url == 
"/test"
:
                ret_data = 
"test"
            
elif 
 url == 
"/home"
:
                ret_data = 
"home"
            
elif
 url == 
"/index"
:
                ret_data = 
"index"
            
else
:
                ret_data = 
"404"
            conn.send(
f'
{ret_data}
'
.encode(
'utf-8'
))
        
except
 Exception:
            
pass
 
         
        conn.close()
 
 
if
 __name__ == 
'__main__'
:
    StartWebServer(
'127.0.0.1'
, 
8000
)/<code>

4.2：简单web服务器：函数版本

<code> 
import
 socket
import
 time
 
def
 
test
(url) 
:

    ret = 
f'test: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
index
(url)
:

    ret = 
f'index: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
home
(url)
:

    ret = 
f'home: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
gettime
(url)
:

    now = time.strftime( 
'%Y-%m-%d %H:%M:%S'
)
    ret = 
f'time: 
{url}
 
{now}
'

    
return
 ret.encode(
'utf-8'
)
 
url_map = {
'/test'
:test,
'/index'
:index,
'/home'
:home,
'/time'
:gettime}
 
 
def
 
handle_client_data
(data)
:

    data = data.decode(
'utf-8'
)
    url = data.split()[
1
]
 
    ret_data = url
    
if
 url 
in
 url_map:
        func = url_map[url]
        ret_data = func(url)
    
else
:
        ret_data = 
b"404"
    
return
 ret_data
 
def
 
StartWebServer
(ip,port)
:

     
    sk = socket.socket()
 
     
    sk.bind((ip,port))
 
     
    sk.listen()
 
     
while
 
True
:
         
        conn, addr = sk.accept()
         
        data = conn.recv(
8096
)
        print(data)
 
         
        conn.send(
b'HTTP/1.1 200 OK\r\n\r\n'
)
 
         
        
try
:
            ret_data = handle_client_data(data)
            conn.send(ret_data)
        
except
 Exception:
            
pass
 
         
        conn.close()
 
if
 __name__ == 
'__main__'
:
    StartWebServer(
'127.0.0.1'
, 
8000
)/<code>

在浏览器中访问：
http://127.0.0.1:8000/time

4.3：简单web服务器：返回动态页面

<code> 
import
 socket
import
 time
 
def
 
test
(url)
:

    ret = 
f'test: 
{url}
'

    
return
 ret.encode(
'utf-8' 
)
 
def
 
index
(url)
:

    
with
 open(
'index.html'
, 
'rb'
) 
as
 f:
        ret = f.read()
        
return
 ret
 
def
 
home
(url)
:

    ret = 
f'home: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
gettime
(url)
:

    now = time.strftime(
'%Y-%m-%d %H:%M:%S'
)
    
with
 open(
'time.html'
, 
'r' 
, encoding=
'utf-8'
) 
as
 f:
        data = f.read()
        data = data.replace(
'##time##'
, now)
        
return
 data.encode(
'utf-8'
)
 
url_map = {
'/test'
:test,
'/index'
:index,
'/home'
:home,
'/time'
:gettime}
 
 
def
 
handle_client_data
(data)
:

    data = data.decode(
'utf-8'
)
    url = data.split()[
1
]
 
    ret_data = url
    
if
 url 
in
 url_map:
        func = url_map[url]
        ret_data = func(url)
    
else
:
        ret_data = 
b"404"
    
return
 ret_data
 
def
 
StartWebServer
(ip,port)
:

     
    sk = socket.socket()
 
     
    sk.bind((ip,port))
 
     
    sk.listen()
 
    
while 
 
True
:
         
        conn, addr = sk.accept()
         
        data = conn.recv(
8096
)
        print(data)
 
         
        conn.send(
b'HTTP/1.1 200 OK\r\n\r\n'
)
 
         
        
try
:
            ret_data = handle_client_data(data)
            conn.send(ret_data)
        
except
 Exception:
            
pass
 
         
        conn.close()
 
if
 __name__ == 
'__main__'
:
    StartWebServer(
'127.0.0.1'
, 
8000
)/<code>

index.html

<code> >
<
html
 
lang
=
"en"
>

<
head
>

    
<
meta
 
charset
=
"UTF-8"
>

    
< 
title
>
index
title
>

head
>

<
body
>

<
div
>

    
<
h1
>
index
h1
>

	
<
h2
>
index
h2
>

	
<
h3
>
index
h3
>

	
< 
h4
>
index
h4
>

div
>

body
>

html
>
/<code>

time.html

<code> >
<
html
 
lang
=
"en"
>

<
head
>

    
<
meta
 
charset
=
"UTF-8"
>

    
<
title
> 
time
title
>

head
>

<
body
>

<
h1
>
当前时间是: ##time## 
h1
>

body
>

html
>
/<code>

4.4：并发web服务器

使用socketserver实现：

<code> 
 
import
 socketserver
import
 time
import
 traceback   
 
 
def
 
test 
(url)
:

    ret = 
f'test: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
index
(url)
:

    
with
 open(
'index.html'
, 
'rb'
) 
as
 f:
        ret = f.read()
        
return
 ret
 
def
 
home
(url)
:

    ret = 
f'home: 
{url}
'

    
return
 ret.encode(
'utf-8'
)
 
def
 
gettime 
(url)
:

    now = time.strftime(
'%Y-%m-%d %H:%M:%S'
)
    
with
 open(
'time.html'
, 
'r'
, encoding=
'utf-8'
) 
as
 f:
        data = f.read()
        data = data.replace(
'##time##'
, now)
        
return
 data.encode(
'utf-8'
)
 
url_map = {
'/test'
:test,
'/index'
:index,
'/home'
:home,
'/time'
:gettime}
 
 
def
 
handle_client_data
(data)
:

    data = data.decode(
'utf-8'
)
    url = data.split()[
1
]
 
    ret_data = url
    
if
 url 
in
 url_map:
        func = url_map[url]
        ret_data = func(url)
    
else
:
        ret_data = 
b"404"
     
return
 ret_data
 
 
 
 
class
 
TcpServer
(socketserver.BaseRequestHandler)
:

    
"""
    必须继承socketserver.BaseRequestHandler类
    """
    
def
 
handle
(self)
:

        
"""
        必须实现这个方法！
        :return:
        """
        conn = self.request          
         
         
        
while
 
True
:
            
try
:
                data = conn.recv(
8096
)
                print(data)
                conn.send(
b'HTTP/1.1 200 OK\r\n\r\n'
)
 
                 
                
try
:
                    ret_data = handle_client_data(data)
                    conn.sendall(ret_data)
                
except
 Exception:
                    
pass
 
                
break
            
except
 Exception:
                val = traceback.format_exc()
                print(val)
                
break
        print(
f'退出客户端
{self.client_address}
的处理。'
)
 
 
def
 
StartTcpServer
(ip,port)
:

     
    server = socketserver.ThreadingTCPServer((ip,port), TcpServer)
    print(
"启动socketserver服务器！"
)
     
    server.serve_forever()
 
if
 __name__ == 
'__main__'
:
    StartTcpServer(
'127.0.0.1'
, 
8000
)/<code>