Skip to content
Related Articles

Related Articles

Improve Article

Python – How to search for a string in text files?

  • Last Updated : 24 Jan, 2021

In this article, we are going to see how to search for a particular string in a text file.

Consider below text File :

Example 1: we are going to search string line by line if the string found then we will print that string and line number.

Steps:



  • Open a file.
  • Set variables index and flag to zero.
  • Run a loop through the file line by line.
  • In that loop check condition using the ‘in’ operator for string present in line or not. If found flag to 0.
  • After loop again check condition for the flag is set or not. If set string found then print a string and line number otherwise simply print the message ‘String not found’.
  • Close a file.

Code:

Python3




string1 = 'coding'
  
# opening a text file
file1 = open("geeks.txt", "r")
  
# setting flag and index to 0
flag = 0
index = 0
  
# Loop through the file line by line
for line in file1:  
    index + = 1 
      
    # checking string is present in line or not
    if string1 in line:
        
      flag = 1
      break 
          
# checking condition for string found or not
if flag == 0
   print('String', string1 , 'Not Found'
else
   print('String', string1, 'Found In Line', index)
  
# closing text file    
file1.close() 

Output:

Example 2: We are just finding string is present in the file or not.

Step:

  • open a file.
  • Read a file and store it in a variable.
  • check condition using ‘in’ operator for string present in the file or not.
  • If the condition true then print the message ‘string is found’ otherwise print ‘string not found’.
  • Close a file.

Code:

Python3




string1 = 'portal'
  
# opening a text file
file1 = open("geeks.txt", "r")
  
# read file content
readfile = file1.read()
  
# checking condition for string found or not
if string1 in readfile: 
    print('String', string1, 'Found In File')
else
    print('String', string1 , 'Not Found'
  
# closing a file
file1.close() 

Output:

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course




My Personal Notes arrow_drop_up
Recommended Articles
Page :