Python: Remove all duplicate elements from a given array

Last update on March 28 2025 12:51:44 (UTC/GMT +8 hours)

23. Remove All Duplicate Elements from an Array

Write a Python program that removes all duplicate elements from an array and returns a new array.

Sample Solution-1:

Python Code:

import array as arr
def test(nums):
    return sorted(set(nums),key=nums.index)

array_num = arr.array('i', [1, 3, 5, 1, 3, 7, 9])
print("Original array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nAfter removing duplicate elements from the said array:")
result = arr.array('i', test(array_num))
for i in range(len(result)):    
    print(result[i], end=' ')
array_num = arr.array('i', [2, 4, 2, 6, 4, 8])
print("\nOriginal array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nAfter removing duplicate elements from the said array:")
result = arr.array('i', test(array_num))
for i in range(len(result)):    
    print(result[i], end=' ')

Sample Output:

Original array:
1 3 5 1 3 7 9 
After removing duplicate elements from the said array:
1 3 5 7 9 
Original array:
2 4 2 6 4 8 
After removing duplicate elements from the said array:
2 4 6 8   

Flowchart:

Sample Solution-2:

Python Code:

import collections
import array as arr
def test(nums):
    return list(collections.OrderedDict.fromkeys(nums))

array_num = arr.array('i', [1, 3, 5, 1, 3, 7, 9])
print("Original array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nAfter removing duplicate elements from the said array:")
result = arr.array('i', test(array_num))
for i in range(len(result)):    
    print(result[i], end=' ')
array_num = arr.array('i', [2, 4, 2, 6, 4, 8])
print("\nOriginal array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nAfter removing duplicate elements from the said array:")
result = arr.array('i', test(array_num))
for i in range(len(result)):    
    print(result[i], end=' ')

Sample Output:

Original array:
1 3 5 1 3 7 9 
After removing duplicate elements from the said array:
1 3 5 7 9 
Original array:
2 4 2 6 4 8 
After removing duplicate elements from the said array:
2 4 6 8 

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to remove duplicates from an array by converting it to a set and then back to an array.
• Write a Python program to iterate over an array and build a new array that contains only the first occurrence of each element.
• Write a Python program to use list comprehension with a helper set to filter out duplicate elements from an array.
• Write a Python program to implement a function that returns a new array with duplicates removed while preserving order.

Python Code Editor:

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