Overview:
- The bind() method of Python's socket class assigns an IP address and a port number to a socket instance.
- The bind() method is used when a socket needs to be made a server socket.
- As server programs listen on published ports, it is required that a port and the IP address to be assigned explicitly to a server socket.
- For client programs, it is not required to bind the socket explicitly to a port. The kernel of the operating system takes care of assigning the source IP and a temporary port number.
- The client socket can use the connect() method, after the socket creation is complete to contact the server socket.
Example – A Simple Echo Server Program:
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import socket
# A TCP based echo server echoSocket = socket.socket();
# Bind the IP address and the port number echoSocket.bind(("127.0.0.1", 32007));
# Listen for incoming connections echoSocket.listen();
# Start accepting client connections while(True): (clientSocket, clientAddress) = echoSocket.accept();
# Handle one request from client while(True): data = clientSocket.recv(1024); print("At Server: %s"%data);
if(data!=b''): # Send back what you received clientSocket.send(data); break; |
Output:
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At Server: b'Learning Python is fun' |
Example – A Simple Echo Client Program:
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import socket
# Create a TCP based client socket echoClient = socket.socket();
# Note: No need for bind() call in client sockets... # Just use the socket by calling connect() echoClient.connect(("127.0.0.1", 32007));
# Send a message echoClient.send("Learning Python is fun".encode());
# Get the reply msgReceived = echoClient.recv(1024);
# Print the reply print("At client: %s"%msgReceived.decode()); |
Output:
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At client: Learning Python is fun |