How to Replace Duplicate Occurrences in a String Using Python

Submitted by razormist on Tuesday, March 25, 2025 - 22:02.

In this tutorial, we’ll learn how to program "How to Replace Duplicate Occurrences in a String Using Python." The objective is to efficiently replace duplicate occurrences in a string. This tutorial will guide you through the process step by step, helping you detect any duplicate occurrences of words in a string and replace them with a specific word. So, let’s get started!

This topic is straightforward to understand. Just follow the instructions I provide, and you’ll complete it with ease. The program I’ll demonstrate will show you the correct and efficient way to check whether duplicate words are present in a string and replace them with a specific word. So, let’s dive into the coding process!

Getting Started:

First you will have to download & install the Python IDLE's, here's the link for the Integrated Development And Learning Environment for Python https://www.python.org/downloads/.

Creating Main Function

This is the main function of the application. The following code will display a simple GUI in terminal console that will display program. To do this, simply copy and paste these blocks of code into the IDLE text editor.

while True:
    print("\n============= Replace Duplicate Occurrences in a String =============\n")
 
    my_str = 'I love programming. I working code'
 
 
    print("Current string: " + str(my_str)) 
 
 
    repl_dict = {'I' : 'Me'} 
 
 
    my_list = my_str.split(' ') 
    res = ' '.join([repl_dict.get(val) if val in repl_dict.keys() and my_list.index(val) != idx 
                                                                else val for idx, val in enumerate(my_list)]) 
 
 
    print("New String: " + str(res)) 
 
    opt = input("\nDo you want to try again?(yes/no): ")
       
    if opt.lower() == 'yes':
        ret=False
    elif opt.lower() == 'no':
        ret=True
        print("Exiting program....")
    else:
        print("Please enter yes/no:")
        break
 
    if ret == False:
        continue

This program replaces duplicate occurrences of specific words in a string, but keeps the first instance unchanged. It uses a dictionary (repl_dict) to define replacements and processes the string by splitting it into words, then reconstructing it while swapping only the duplicates. It keeps running until the user decides to exit.

Output:

There you have it we successfully created How to Replace Duplicate Occurrences in a String Using Python. I hope that this simple tutorial help you to what you are looking for. For more updates and tutorials just kindly visit this site. Enjoy Coding!

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