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PUBLISHED ON: JULY 2, 2021

# Remove all duplicates from a given string in Python

In this tutorial, you will learn to remove all duplicates from a given string in Python. Strings in Python are a sequence of characters wrapped inside single, double, or triple quotes. For a given string we have to remove all the characters which occur more than once in the string. We will follow the order in which the characters appear. For example,

Input: "stringis"

Output: "string"

To solve this problem, there are several different approaches,

1. using OrderedDict() and fromkeys() function
2. using OrderedDict() function and set approach

We will look at these approaches separately

## Approach 1: using OrderedDict() function

In this approach, we will use the OrderedDict() method from the collections class and fromkeys() in our program.

OrderedDict is a dictionary subclass that remembers the order of the keys that were inserted first. Since there can't be duplicate keys this method will return the string after removing the duplicate characters.

### Algorithm

Follow the algorithm to understand the approach better:

Step 1- Import OrderedDict from collections class

Step 2- Define a function that will remove duplicates

Step 3- Declare a string with characters

Step 4- Call function to remove characters in that string

Step 5- Print value returned by the function

### Python Program 1

Look at the program to understand the implementation of the above-mentioned approach.

``````from collections import OrderedDict

def remove_duplicate(s):
return "".join(OrderedDict.fromkeys(s))

# test
s="abcfgbsca"
print(s)
print("After removing duplicates: ",remove_duplicate(s))``````

abcfgbsca
After removing duplicates: abcfgs

## Approach 2: OrderedDict

In this approach, we will convert the string to a set by using the set() method. Then we will declare another string and store characters that are not already in the string. This new string will contain the resultant string.

### Algorithm

Follow the algorithm to understand the approach better

Step 1- Import OrderedDict from collections class

Step 2- Define a function that will remove duplicates

Step 3- Create a set of string and store

Step 4- Declare a new empty string

Step 5- Run a loop and add each character in the empty string if it is already not present in the string

Step 6- Print the string

### Python Program 2

Look at the program to understand the implementation of the above-mentioned approach.

``````# remove duplicates in string

from collections import OrderedDict

def remove_duplicate(s):
string=set(s)
string="".join(string)
dup=""
for i in s:
if(i in dup):
pass
else:
dup=dup+i
print("After removing: ",dup)

s="stdsrdthw"
print(s)
print(remove_duplicate(s))``````

stdsrdthw
After removing: stdrhw

## Conclusion

In this tutorial, we have discussed two approaches for removing duplicates from a string. We have also discussed how to use methods of the collection class and use them to remove duplicates.

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