This is the server side:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
import socketserver class MyTCPHandler(socketserver.BaseRequestHandler): """ The request handler class for our server. It is instantiated once per connection to the server, and must override the handle() method to implement communication to the client. """ def handle(self): # self.request is the TCP socket connected to the client self.data = self.request.recv(1024).strip() print("{} wrote:".format(self.client_address[0])) print(self.data) # just send back the same data, but upper-cased self.request.sendall(self.data.upper()) if __name__ == "__main__": HOST, PORT = "localhost", 9999 # Create the server, binding to localhost on port 9999 with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server: # Activate the server; this will keep running until you # interrupt the program with Ctrl-C server.serve_forever()
An alternative request handler class that makes use of streams (file-like objects that simplify communication by providing the standard file interface):
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
class MyTCPHandler(socketserver.StreamRequestHandler): def handle(self): # self.rfile is a file-like object created by the handler; # we can now use e.g. readline() instead of raw recv() calls self.data = self.rfile.readline().strip() print("{} wrote:".format(self.client_address[0])) print(self.data) # Likewise, self.wfile is a file-like object used to write back # to the client self.wfile.write(self.data.upper())
The difference is that the readline()
call in the second handler will call recv()
multiple times until it encounters a newline character, while the single recv()
call in the first handler will just return what has been sent from the client in one sendall()
call.
This is the client side:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
import socket import sys HOST, PORT = "localhost", 9999 data = " ".join(sys.argv[1:]) # Create a socket (SOCK_STREAM means a TCP socket) with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock: # Connect to server and send data sock.connect((HOST, PORT)) sock.sendall(bytes(data + " ", "utf-8")) # Receive data from the server and shut down received = str(sock.recv(1024), "utf-8") print("Sent: {}".format(data)) print("Received: {}".format(received))