如何从对列表中返回唯一值？

def unique_values_set(lst):
    unique_set = set(lst)
    unique_list = list(unique_set)
    return unique_list

# 示例用法
my_list = [1, 2, 3, 3, 4, 5, 5, 6]
unique_list = unique_values_set(my_list)
print(unique_list)

def unique_values_loop(lst):
    unique_list = []
    for item in lst:
        if item not in unique_list:
            unique_list.append(item)
    return unique_list

# 示例用法
my_list = [1, 2, 3, 3, 4, 5, 5, 6]
unique_list = unique_values_loop(my_list)
print(unique_list)

def unique_values_list_comprehension(lst):
    unique_list = [x for i, x in enumerate(lst) if x not in lst[:i]]
    return unique_list

# 示例用法
my_list = [1, 2, 3, 3, 4, 5, 5, 6]
unique_list = unique_values_list_comprehension(my_list)
print(unique_list)