Python列表去重

list_1=[10, 1, 2, 20, 10, 3, 2, 1, 15, 20, 44, 56, 3, 2, 1]
def func1(list_1):
   return list(set(list_1))
print('去重后的列表:',func1(list_1))

list_2 = [10, 1, 2, 20, 10, 3, 2, 1, 15, 20, 44, 56, 3, 2, 1]
def func2(list_2):
    #定义一个空列表
    mylist_2=[]
    #i遍历list_2
    for i in list_2:
        #如果i不在mylist_2，则添加到mylist_2
        if i not in mylist_2:
            mylist_2.append(i)
    print(mylist_2)
print(func2(list_2))

list_3 = [10, 1, 2, 20, 10, 3, 2, 1, 15, 20, 44, 56, 3, 2, 1]
def func3(list_3):
  result_list=[]
  temp_list=sorted(list_3)
  i=0
  while i<len(temp_list):
      #如果不在result_list则添加进去，否则i+1
    if temp_list[i] not in result_list:
      result_list.append(temp_list[i])
    else:
      i+=1
  return result_list
print(func3(list_3))

list_4= [10, 1, 2, 20, 10, 3, 2, 1, 15, 20, 44, 56, 3, 2, 1]
def func4(list_4):
    #fromkeys() 函数创建一个新字典，获取新字典的键（键值是唯一的）
    result_list = []
    for i in {}.fromkeys(list_4).keys():
        result_list.append(i)
    return result_list
print(func4(list_4))

import itertools
list_5= [10, 1, 2, 20, 10, 3, 2, 1, 15, 20, 44, 56, 3, 2, 1]
def func5(list_5):
    list_5.sort()
    temp_list= itertools.groupby(list_5)
    result_list=[]
    for i,j in temp_list:
        result_list.append(i)
    return result_list
print(func5(list_5))