python怎么去重

>>> lst1 = [2, 1, 3, 4, 1]
>>> lst2 = list(set(lst1))
>>> print(lst2)
[1, 2, 3, 4]

>>> lst1 = [2, 1, 3, 4, 1]
>>> lst2 = {}.fromkeys(lst1).keys()
>>> print(lst2)
dict_keys([2, 1, 3, 4])

>>> lst1 = [2, 1, 3, 4, 1]
>>> temp = []
>>> for item in lst1:
    if not item in temp:
    temp.append(item)
>>> print(temp)
[2, 1, 3, 4]

>>> lst1 = [2, 1, 3, 4, 1]
>>> temp = []
>>> [temp.append(i) for i in lst1 if not i in temp]
[None, None, None, None]
>>> print(temp)
[2, 1, 3, 4]

>>> lst1 = [2, 1, 3, 4, 1]
>>> lst2.sort(key=lst1.index)
>>> print(lst2)
[2, 1, 3, 4]

>>> lst1 = [2, 1, 3, 4, 1]
>>> lst2 = sorted(set(lst1), key=lst1.index)
>>> print(lst2)
[2, 1, 3, 4]

>>> data = [2, 1, 3, 4, 1]
>>> [item for item in data if data.count(item) == 1]

>>> data = [2, 1, 3, 4, 1]
>>> list(filter(lambda x:data.count(x) == 1, data))
[2, 3, 4]