#列表去重
L =[1,2,3,4,5,6,6,5,4,3,2,1]
#創建壹個空字典
d ={}
#用字典的fromkeys()方法去重,得到壹個字典,去重之後的元素為鍵,值為None的字典
#{1:None, 2:None, 3:None, 4:None, 5:None, 6:None}
#fromkeys(iterable,value=None)
L = d.fromkeys(L)
print(L) #{1:None, 2:None, 3:None, 4:None, 5:None, 6:None}
#用字典的keys()方法得到壹個類似列表的東西,但不是列表。Keys()函數返回的是壹個dict_keys對象:
#以字典的鍵作為元素的壹個類列表
L = L.keys()
#print(L) #dict_keys([1,2,3,4,5,6])
L = list(L)
print(L) #[1,2,3,4,5,6]
#可以用列表的sort()方法排序,默認是升序
# print(L.sort())
L.sort(reverse=True) #升序
print(L)#[6,5,4,3,2,1]
print('--------------------------')
2、集合,集合是可叠代的
L2 = [1,2,3,4,5,6,6,5,4,3,2,1]
L2 = set(L2)
print(L2) #{1,2,3,4,5,6}
L2 = list(L2)
print(L2) #[1,2,3,4,5,6]
print('-------------------------------')
3、用for循環
L3 = [1,2,3,4,5,6,6,5,4,3,2,1]
L4 = []
for x in L3:
if x not in L4:
L4.append(x)
print(L4) #[1,2,3,4,5,6]