In this article, we are going to know how to make a simple calculator in Python socket programming.
Prerequisite: Socket Programming in Python.
First, we will understand the basics of Python socket programming. Socket programming is used to set up a communication channel between two nodes on a network. It provides Inter connected communication (IPC). The network can be a logical, local network and physical network to connect external network. In this example, we will write local socket programming code in Python.
Socket Module
Python has a remarkably large library of functional modules from which we are going to use the Socket module. This module provides us to make networking programs in Python. In this module, we will be focused on connect method and socket method.
- socket() method helps to make socket INET stream.
- connect() method helps to connect the server.
Methode used
Syntax: socket.socket(socket.AF_INET, socket.SOCK_STREAM)
Parameters:
- socket.AF_INET: It refers to the address-family ipv4.
- socket.SOCK_STREAM: It refers to connection-oriented TCP protocol.
Syntax: socket.connect(IP Address of the Server,Port Number)
Parameters:
- IP Address: IP address of the server.
- Port Number: Port Number on which we have to connect.
Note: To establish the connection between the client and server we have to run the Python server program first and then run the Python client program otherwise if we run the client program first it gives a connection error.
Python Client
First, we will write client-side code. A client is a user or machine which generates a request to the server in return it gets the response from the server side. To perform these tasks we have to know two things which are the Port Number and IP Address of the Server.
In this case, We will use localhost IP which is 127.0.0.1 and the port number is “8080”.
Python3
# Import socket module import socket # In this Line we define our local host # address with port number SERVER = "127.0.0.1" PORT = 8080 # Making a socket instance client = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # connect to the server client.connect((SERVER, PORT)) # Running a infinite loop while True : print ( "Example : 4 + 5" ) # here we get the input from the user inp = input ("Enter the operation in \ the form opreand operator oprenad: ") # If user wants to terminate # the server connection he can type Over if inp = = "Over" : break # Here we send the user input # to server socket by send Method client.send(inp.encode()) # Here we received output from the server socket answer = client.recv( 1024 ) print ( "Answer is " + answer.decode()) print ( "Type 'Over' to terminate" ) client.close() |
Python Server
The server-side is a machine on which all the operations are executed as requested by the client-side, we will perform addition, subtraction, multiplication, and division operation on the server. To do so the server received input from a client and performs the basic operation by itself. when the result is ready Python server then sends the output to the client machine.
Python3
# Import socket module import socket # Here we use localhost ip address # and port number LOCALHOST = "127.0.0.1" PORT = 8080 # calling server socket method server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind((LOCALHOST, PORT)) server.listen( 1 ) print ( "Server started" ) print ( "Waiting for client request.." ) # Here server socket is ready for # get input from the user clientConnection, clientAddress = server.accept() print ( "Connected client :" , clientAddress) msg = '' # Running infinite loop while True : data = clientConnection.recv( 1024 ) msg = data.decode() if msg = = 'Over' : print ( "Connection is Over" ) break print ( "Equation is received" ) result = 0 operation_list = msg.split() oprnd1 = operation_list[ 0 ] operation = operation_list[ 1 ] oprnd2 = operation_list[ 2 ] # here we change str to int conversion num1 = int (oprnd1) num2 = int (oprnd2) # Here we are perform basic arithmetic operation if operation = = "+" : result = num1 + num2 elif operation = = "-" : result = num1 - num2 elif operation = = "/" : result = num1 / num2 elif operation = = "*" : result = num1 * num2 print ( "Send the result to client" ) # Here we change int to string and # after encode send the output to client output = str (result) clientConnection.send(output.encode()) clientConnection.close() |
Output: