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].
Input: A list of integers.
Output: The list of integers.
题目来自 py.checkio.org
My answer:
找到出现次数为1的元素，删除
def checkio(data):
temp=data.copy()
for i in temp:
print(data.count(i))
if data.count(i)==1:
data.remove(i)
return data
Other answer:
def checkio(data): return [i for i in data if data.count(i) > 1]