python 如何获取多维列表中子列表出现的次数？而不是最小单位元素出现的次数？

Question

如图：

请问有没有办法统计article[][]在article中出现的次数，而不是article[][][]？即['a','b']这样的列表在article中出现的次数。谢谢~~~

原始代码如下：
article = []
sentence0 = [['a','b'],[3,4]]
sentence1 = [[5,'b'],[7,8]]

article.append(sentence0)
article.append(sentence1)
print (article)
print (article[1])
print (article1)
print (article1[0])

import collections
import numpy as np
import random
import time

def list_to_dict(lst):

dic = {}
for i in lst:
    dic[i] = lst.count(i)
return dic

def collect(lst):

return dict(collections.Counter(lst))

def unique(lst):

return dict(zip(*np.unique(lst, return_counts=True)))

dict1 = unique(article)
print(dict1)

Answer 1

sentence0 = [['a','b'],[3,4],[1,2,3],[12,3]]
sentence1 = [[5,'b'],[7,8]]

def print_count(l):
    count = 0
    for i in l:
        if isinstance(i, list):
            count += 1
            print_count(i)
    return count


print(print_count(sentence0))     //打印4
print(print_count(sentence1))     //打印2