diff --git a/libs/langchain/langchain/retrievers/document_compressors/listwise_rerank.py b/libs/langchain/langchain/retrievers/document_compressors/listwise_rerank.py index 4b83073b86b..182fd3f7be4 100644 --- a/libs/langchain/langchain/retrievers/document_compressors/listwise_rerank.py +++ b/libs/langchain/langchain/retrievers/document_compressors/listwise_rerank.py @@ -24,7 +24,10 @@ def _get_prompt_input(input_: dict) -> dict[str, Any]: context = "" for index, doc in enumerate(documents): context += f"Document ID: {index}\n```{doc.page_content}```\n\n" - context += f"Documents = [Document ID: 0, ..., Document ID: {len(documents) - 1}]" + document_range = "empty list" + if len(documents) > 0: + document_range = f"Document ID: 0, ..., Document ID: {len(documents) - 1}" + context += f"Documents = [{document_range}]" return {"query": input_["query"], "context": context}