通过Counter统计列表元素出现次数，获取列表重复元素，参考代码如下
from collections import Counter #
ls = [1,24,56,6,7,8,54,4,4,5,6,7,8]
b = dict(Counter(ls))
print ([key for key,value in b.items()if value > 1]) #只展示重复元素
print ({key:value for key,value in b.items()if value > 1}) #展现重复元素和重复次数参考资料：链接
