sentence_rank.py

sentence_rank={}
for sent in doc.sents:
    for word in sent :       
        if word.text.lower() in word_frequency.keys():            
            if sent in sentence_rank.keys():
                sentence_rank[sent]+=word_frequency[word.text.lower()]
            else:
                sentence_rank[sent]=word_frequency[word.text.lower()]

top_sentences=(sorted(sentence_rank.values())[::-1])
top_sent=top_sentences[:3]