Python Program to Remove Repeated Character from String

In Python, strings are one of the most commonly used data types, and it is quite common to come across a situation where we need to remove repeated characters from a string. In this post, we will learn the different approaches to remove repeated characters from a given string in Python.

For Examples

1. Input: “hello” Output: “helo”
2. Input: “Mississippi” Output: “Misp”

Method 1: Using a Set and String Concatenation

In this approach, We will be using a set to store the unique characters of the string, and string concatenation to create the output string.

def remove_duplicates(s):
    unique_chars = set()
    output = ""
    for char in s:
        if char not in unique_chars:
            unique_chars.add(char)
            output += char
    return output
string = input("Please Enter a string: ")
print(remove_duplicates(string))

Output

Please Enter a string: programming
progamin

Method 2: Using a List and Join

In this method, we will use a list to store the all unique characters of the string. After that, we will use the join method to create the output string.

def remove_duplicates(s):
    unique_chars = []
    for char in s:
        if char not in unique_chars:
            unique_chars.append(char)
    return "".join(unique_chars)
string = input("Please Enter a string: ")
print(remove_duplicates(string))

Output

Please Enter a string: hello
helo