Python 两个列表元素包含判断

需求：有A=[1,2，2,3]  B=[1,5,2,8,2,6,3] 判断A的元素是否全在B中，且元素出现次数也是包含关系。

代码实现：

import collections

def inn(a,b):
    dic1 = {}
    dic2 = {}
    t = 0
    d1 = collections.Counter(a)
    d2 = collections.Counter(b)
    for k in d1:
        dic1[k]=d1[k]
    for k in d2:
        dic2[k] = d2[k]
    try:
        for i in dic1.keys():
            if dic2[i] >= dic1[i]:
                t += 1
        if t == len(dic1):
            return True
        else:
            return False
    except KeyError:
        return False