遍历去重

>>> 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]

推导式去重

>>> 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]

双指针去重

i,j两个指针分别指向第i个和第i+1个元素，比较，相等j后移，直到不等将第i个元素加到新列表。j赋给i，开始下一次循环即可。

def uniqList03(data=None):
    data = sorted(data)
    newdata = []
    stop = len(data) - 1
    i = 0
    while i <= stop:
        j = i + 1
        if i == stop:
            newdata.append(data[i])
            i += 1
        else:
            if data[i] == data[j]:
                while j <= stop and data[i] == data[j]:
                    j += 1
            newdata.append(data[i])
            i = j
    return newdata