clock  Mon - Sun 8.00 AM - 8.00 PM
play store

Python Code to Search and Replace a String in a Text File

writter  Sumit Dey Sarkar
Date  30 Apr 2023
Language  Python
Python Code to Search and Replace a String in a Text File

Python Code to Search and Replace a String in a Text File

In this tutorial we will learn Python code to search and replace a string in a text file.


Python Code to Search and Replace a String in a Text File


Python code to search and replace a string in a text file

Using Python, you can use the built-in re module, which offers regular expression matching operations, to search and replace a string in a text file.


Here's an example code:

import re

# define the search and replace strings
search_str = 'old_string'
replace_str = 'new_string'

# read the input file
with open('input.txt', 'r') as file:
    filedata =

# perform the search and replace operation using re.sub()
newdata = re.sub(search_str, replace_str, filedata)

# write the modified data to the output file
with open('output.txt', 'w') as file:

In this example, the re.sub() method is used to replace all occurrences of the search_str with replace_str in the filedata. The modified data is then written to a new file named output.txt.


You can modify the search_str and replace_str variables according to your needs. You need confirm that the input file input.txt is present in the current working directory.


Comments 0

Leave a comment

Coursera, Codeacademy, Udacity, W3Schools, Udemy, Alison, TheNewBoston, edX, P.S.Codewars,Freecodecamp, Managing technical debt blog, Scrimba, Codepen, Codepen/challenges, The Odin Project, htmlreference.​io, cssreference.​io, Frontend Mentor, Dev Challenges, MDN, Code Mentor, Coding Dojo, CSS Battle, Codier, Ace Frontend, Can I Use, CSS Tricks, 30 Seconds of Code,tutorialspoint, Neumorphism, Shaddows Brumm, Fancy Border Radius, Glow Generator, Clothoid Corners, Glassmorphism, Clipy, CSS Filters, Base64 Image, Quantity Queries, Animations, Cubic-Bezier, Keyframes, Wait Animate, Transition.Style, graphic design, web design, website design, website builder, web developer, web designer, webdesign, ecommerce website, web design company, website creator, website designer, responsive web design, web development company, best website design, web design software, web page design, build a website, web developer salary, design website, web design courses, how to design a website, web design inspiration, website layout, web designer salary, web application development, ecommerce website design, web agency, software development company, web design tutorial, web programming, design company, website design templates, what is web designing, web developer jobs, website developer, web design agency, freelance web developer, web design services, freelance web designer, graphic design websites, web solutions, ecommerce website development, free website design, web development courses, webdev, web developers, web development tools, website design services, developpeur web, web design london, website design ideas, web designing and programming, design a website, web design and development, web dev, web development services, homepage design, best designed websites, cheap website design, learn web design, web design templates, web design tools, web design jobs, website design inspiration, web design india, flash website, website developers, designer websites, website services, website design cost, good website design, site design, simple website design, cool website designs, modern website design, graphic designer websites, webcode, best web design software, website making, free web design software, mobile website design, learn web development, front end web developer, how to become a web developer, web developer portfolio, web development company in india, python web development, web development tutorial, website company, website design and development, web company, webdesigning, professional website design, affordable web design, best web design company, creative web design, top website designs, website design pricing, web developer tools, how to develop a website