initialization with empty corpus results in ZeroDivisionError #36
Description
rank-bm25==0.2.2
In [11]: rank_bm25.BM25(corpus=[])
---------------------------------------------------------------------------
ZeroDivisionError Traceback (most recent call last)
Cell In[11], line 1
----> 1 rank_bm25.BM25(corpus=[])
File .../lib/python3.11/site-packages/rank_bm25.py:27, in BM25.__init__(self, corpus, tokenizer)
24 if tokenizer:
25 corpus = self._tokenize_corpus(corpus)
---> 27 nd = self._initialize(corpus)
28 self._calc_idf(nd)
File .../lib/python3.11/site-packages/rank_bm25.py:52, in BM25._initialize(self, corpus)
48 nd[word] = 1
50 self.corpus_size += 1
---> 52 self.avgdl = num_doc / self.corpus_size
53 return nd
ZeroDivisionError: division by zero