set(): Remove Duplicates Easily

Remove duplicates from a list

nums = [1, 2, 2, 3, 4, 4, 5]
unique = set(nums)
print(unique)

# {1, 2, 3, 4, 5}

Back to list

nums = [1, 2, 2, 3, 4, 4, 5]
unique_list = list(set(nums))
print(unique_list)

# [1, 2, 3, 4, 5]

Preserve order (Python 3.7+)

nums = [3, 1, 2, 3, 2, 1]
unique_ordered = list(dict.fromkeys(nums))
print(unique_ordered)

# [3, 1, 2]

Conclusion

Using set() is the fastest way to remove duplicates, but if you also need to preserve the original order, use dict.fromkeys().