过滤器列表，只有唯一值 - 与python

Question

我想知道我将如何采取一个列表，例如= [1,5,2,5,1]，并让它过滤出唯一值，以便它只返回一个只在列表中出现一次的数字。所以它会给我一个结果= [2]。

我能弄清楚如何过滤掉重复，现在我该如何摆脱重复？

无需直答案，只是有一些小技巧或暗示都是欢迎的。

我能找到这个计算器上。它做我想要的，但我不明白的代码，但有人可以为我分解？

d = {} 
for i in l: d[i] = d.has_key(i) 

[k for k in d.keys() if not d[k]] 

Answer 1

>>> a = [1, 5, 2, 5, 1] 
>>> from collections import Counter 
>>> [k for k, c in Counter(a).iteritems() if c == 1] 
[2] 

Answer 2

听到的是你的代码做什么：

d = {} 
for i in list: 
    # if the item is already in the dictionary then map it to True, 
    # otherwise map it to False 
    # the first time a given item is seen it will be assigned False, 
    # the next time True 
    d[i] = d.has_key(i) 

# pull out all the keys in the dictionary that are equal to False 
# these are items in the original list that were only seen once in the loop 
[k for k in d.keys() if not d[k]]