defaultdict sample III : inverted_index

 from collections import defaultdict

documents = {1:'defaultdict is amazing',2:'collectios includes defaultdict',3:'defaultdict is amazing collectios includes defaultdict'}

inverted_index = defaultdict(set)

for doc_id , content in documents.items():

  for word in content.split():

    inverted_index[word].add(doc_id)

for i in inverted_index.items():

  print(*i)

Output:

defaultdict {1, 2, 3}

is {1, 3}

amazing {1, 3}

collectios {2, 3}

includes {2, 3}