Add a ListRerank document compressor (#13311)

- **Description:** This PR adds a new document compressor called
`ListRerank`. It's derived from `BaseDocumentCompressor`. It's a near
exact implementation of introduced by this paper: [Zero-Shot Listwise
Document Reranking with a Large Language
Model](https://arxiv.org/pdf/2305.02156.pdf) which it finds to
outperform pointwise reranking, which is somewhat implemented in
LangChain as
[LLMChainFilter](https://github.com/langchain-ai/langchain/blob/master/libs/langchain/langchain/retrievers/document_compressors/chain_filter.py).
- **Issue:** None
- **Dependencies:** None
- **Tag maintainer:** @hwchase17 @izzymsft
- **Twitter handle:** @HarrisEMitchell

Notes:
1. I didn't add anything to `docs`. I wasn't exactly sure which patterns
to follow as [cohere reranker is under
Retrievers](https://python.langchain.com/docs/integrations/retrievers/cohere-reranker)
with other external document retrieval integrations, but other
contextual compression is
[here](https://python.langchain.com/docs/modules/data_connection/retrievers/contextual_compression/).
Happy to contribute to either with some direction.
2. I followed syntax, docstrings, implementation patterns, etc. as well
as I could looking at nearby modules. One thing I didn't do was put the
default prompt in a separate `.py` file like [Chain
Filter](https://github.com/langchain-ai/langchain/blob/master/libs/langchain/langchain/retrievers/document_compressors/chain_filter_prompt.py)
and [Chain
Extract](https://github.com/langchain-ai/langchain/blob/master/libs/langchain/langchain/retrievers/document_compressors/chain_extract_prompt.py).
Happy to follow that pattern if it would be preferred.

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
Co-authored-by: Bagatur <baskaryan@gmail.com>
Co-authored-by: Chester Curme <chester.curme@gmail.com>
This commit is contained in:
Evan Harris
2024-07-18 14:34:38 -06:00
committed by GitHub
parent 4c651ba13a
commit 61ea7bf60b
6 changed files with 228 additions and 1 deletions

View File

@@ -220,6 +220,57 @@
"pretty_print_docs(compressed_docs)"
]
},
{
"cell_type": "markdown",
"id": "14002ec8-7ee5-4f91-9315-dd21c3808776",
"metadata": {},
"source": [
"### `LLMListwiseRerank`\n",
"\n",
"[LLMListwiseRerank](https://api.python.langchain.com/en/latest/retrievers/langchain.retrievers.document_compressors.listwise_rerank.LLMListwiseRerank.html) uses [zero-shot listwise document reranking](https://arxiv.org/pdf/2305.02156) and functions similarly to `LLMChainFilter` as a robust but more expensive option. It is recommended to use a more powerful LLM.\n",
"\n",
"Note that `LLMListwiseRerank` requires a model with the [with_structured_output](/docs/integrations/chat/) method implemented."
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "4ab9ee9f-917e-4d6f-9344-eb7f01533228",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Document 1:\n",
"\n",
"Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while youre at it, pass the Disclose Act so Americans can know who is funding our elections. \n",
"\n",
"Tonight, Id like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service. \n",
"\n",
"One of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court. \n",
"\n",
"And I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nations top legal minds, who will continue Justice Breyers legacy of excellence.\n"
]
}
],
"source": [
"from langchain.retrievers.document_compressors import LLMListwiseRerank\n",
"from langchain_openai import ChatOpenAI\n",
"\n",
"llm = ChatOpenAI(model=\"gpt-3.5-turbo-0125\", temperature=0)\n",
"\n",
"_filter = LLMListwiseRerank.from_llm(llm, top_n=1)\n",
"compression_retriever = ContextualCompressionRetriever(\n",
" base_compressor=_filter, base_retriever=retriever\n",
")\n",
"\n",
"compressed_docs = compression_retriever.invoke(\n",
" \"What did the president say about Ketanji Jackson Brown\"\n",
")\n",
"pretty_print_docs(compressed_docs)"
]
},
{
"cell_type": "markdown",
"id": "7194da42",
@@ -295,7 +346,7 @@
},
{
"cell_type": "code",
"execution_count": 7,
"execution_count": 8,
"id": "617a1756",
"metadata": {},
"outputs": [],