Removing Duplicates from a List While Preserving Order

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

# Example usage:
my_list = [1, 2, 2, 3, 4, 2, 5, 1]
unique_list = remove_duplicates_preserve_order(my_list)
print(f"Original list: {my_list}")
print(f"List after removing duplicates: {unique_list}")

How it works: This snippet demonstrates how to remove duplicate items from a list while keeping the remaining elements in their original order. It achieves this by iterating through the input list and using a `set` named `seen` to efficiently track elements already encountered. If an item is not in `seen`, it's added to both `seen` and the `result` list. This approach leverages the O(1) average time complexity of set lookups for optimal performance.