为这个列表推导式什么无法去重？

def remove_repeat(num_list):
    tmp_list = []
    tmp_list = [i for i in num_list if i not in tmp_list]
    return tmp_list



if __name__ == '__main__':
    num_list = [1,1,2,4,4,1,3,4,3,3,6,5,5,6,2]
    # print(remove_repeat_simple1(num_list))
    # print(remove_repeat_simple2(num_list))
    print(remove_repeat(num_list))