How to pass the nodes for BM25Retriever from VectorStoreIndex

[Alnasser0]

Hello, how can I pass the nodes to BM25Retriever?

My current code is below but it gives me an error:

``
self.bm25_retriever = BM25Retriever.from_defaults(nodes=vector_index.docstore.docs.values(),similarity_top_k=similarity_top_k)

Error:

Cell In[30], line 10
---> 10 self.bm25_retriever = BM25Retriever.from_defaults(nodes=vector_index.docstore.docs.values(),similarity_top_k=similarity_top_k)

File c:\Users\Mahou\miniconda3\envs\bot8\lib\site-packages\llama_index\retrievers\bm25\base.py:130, in BM25Retriever.from_defaults(cls, index, nodes, docstore, stemmer, language, similarity_top_k, verbose, skip_stemming, token_pattern, tokenizer)
    128 # ensure only one of index, nodes, or docstore is passed
    129 if sum(bool(val) for val in [index, nodes, docstore]) != 1:
--> 130     raise ValueError("Please pass exactly one of index, nodes, or docstore.")
    132 if index is not None:
    133     docstore = index.docstore

ValueError: Please pass exactly one of index, nodes, or docstore.

[dosubot[bot]]

To resolve the "Please pass exactly one of index, nodes, or docstore" error when passing nodes to BM25Retriever, ensure that you are providing only one of the index, nodes, or docstore arguments. Here's how you can correctly pass the nodes:

from llama_index.retrievers.bm25 import BM25Retriever
import Stemmer

# Assuming you have a list of nodes from your VectorStoreIndex
nodes = vector_index.docstore.docs.values()

# Initialize the BM25Retriever with the nodes
bm25_retriever = BM25Retriever.from_defaults(
    nodes=nodes,
    similarity_top_k=similarity_top_k,
    stemmer=Stemmer.Stemmer("english"),
    language="english",
)

Make sure that you are not passing both nodes and any other argument like index or docstore at the same time. This should resolve the error you're encountering ^[1].

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