python def unique_preserve_order(lst): seen = set() result = [] for item in lst: if item not in seen: seen.add(item) result.append(item) return result

Пример использования:

print(unique_preserve_order([1, 2, 2, 3, 4, 3, 5])) # Выведет [1, 2, 3, 4, 5]