Deduplicate a List While Preserving Order

def deduplicate_list_preserve_order(input_list):
    seen = set()
    deduplicated = []
    for item in input_list:
        if item not in seen:
            seen.add(item)
            deduplicated.append(item)
    return deduplicated

# Example Usage:
my_list = [1, 2, 2, 3, 4, 3, 5, 1]
unique_list = deduplicate_list_preserve_order(my_list)
# unique_list will be [1, 2, 3, 4, 5]
print(f"Original list: {my_list}")
print(f"Deduplicated (order preserved): {unique_list}")

# For simple deduplication where order doesn't matter, you can use:
# unique_set = list(set(my_list))

How it works: This snippet defines a function `deduplicate_list_preserve_order` that takes a list and returns a new list containing only unique elements, maintaining their original order of appearance. It achieves this by iterating through the input list, using a `set` called `seen` to keep track of elements already encountered. If an element has not been seen before, it's added to both the `seen` set and the `deduplicated` result list. This approach ensures efficient `O(1)` average time complexity for checking uniqueness while preserving the element order.