Non-unique Elements

You are given a non-empty list of integers (X). For this task, you should return a list consisting of only the non-unique elements in this list. To do so you will need to remove all unique elements (elements which are contained in a given list only once). When solving this task, do not change the order of the list. Example: [1, 2, 3, 1, 3] 1 and 3 non-unique elements and result will be [1, 3, 1, 3].

题目大义：将数组中唯一的元素清除

还是C语言的思想，直接粗暴，首先是遍历求出唯一的元素，再使用数组的remove方法

 1 def checkio(data): 2      3     only = [] 4  5     for each in data: 6         count = 0 7         for other in data: 8             if each == other: 9                 count += 110 11         if count == 1:12             only.append(each)13 14     for each in only:15         data.remove(each)16 17     return data

当然我们有更高级的方法list = [x for x in data if x.count > 1]，简单明了，使用了数组的另一种构造方法，使用了数组count方法

1 def checkio(data):2     list = [x for x in data if data.count(x) > 1]3     return list

新技能get