python substitute a string in file code example

Example 1: python replace string in file

#input file
fin = open("data.txt", "rt")
#output file to write the result to
fout = open("out.txt", "wt")
#for each line in the input file
for line in fin:
	#read replace the string and write to output file
	fout.write(line.replace('pyton', 'python'))
#close input and output files
fin.close()
fout.close()

Example 2: change part of a text file python

#!/usr/bin/env python3
import fileinput

with fileinput.FileInput(filename, inplace=True, backup='.bak') as file:
    for line in file:
        print(line.replace(text_to_search, replacement_text), end='')