Using Python to Retrieve Port Numbers from Protocol and Vice Versa

Introduction

In this blog post, we will explore a useful Python technique that allows you to extract port numbers from protocols (aka schemes), and vice versa. This functionality can be particularly handy when working with network programming, web scraping, or building applications that require handling different protocols. Let’s dive into the details and learn how to leverage Python to simplify this process

Extracting Port Numbers from Protocols

To retrieve a port number from a protocol, you can use the Python socket module. Follow these steps:

Step 1: Import the socket module

import socket

Step 2: Use the getservbyname() function

port = socket.getservbyname('http')
print("Port number for HTTP:", port)

Replace 'http' with the desired protocol to get the associated port number.

The getservbyname() function looks up the port number in the system’s services database and returns it.

Mapping Port Numbers to Protocols

Conversely, you can map port numbers to their corresponding protocols using the getservbyport() function. Here’s how:

Step 1: Import the socket module:

import socket

Step 2: Use the getservbyport() function

service = socket.getservbyport(80)
print("Service for port 80:", service)

Replace 80 with the desired port number to retrieve the associated protocol name. The getservbyport() function queries the system’s services database and returns the name of the service.

Conclusion

Python’s socket module provides convenient functions like getservbyname() and getservbyport() to facilitate the retrieval of port numbers from protocols and vice versa. These techniques can streamline your network programming tasks, web scraping projects, or any application where working with different protocols is essential. By leveraging these functionalities, you can enhance the versatility and efficiency of your Python projects.

Remember to handle exceptions and ensure that the necessary ports and services are defined in the system’s services database for accurate results. Happy coding!