Source code for langchain_community.retrievers.wikipedia

from typing import List

from langchain_core.callbacks import CallbackManagerForRetrieverRun
from langchain_core.documents import Document
from langchain_core.retrievers import BaseRetriever

from langchain_community.utilities.wikipedia import WikipediaAPIWrapper


[docs] class WikipediaRetriever(BaseRetriever, WikipediaAPIWrapper): """`Wikipedia API` retriever. Setup: Install the ``wikipedia`` dependency: .. code-block:: bash pip install -U wikipedia Instantiate: .. code-block:: python from langchain_community.retrievers import WikipediaRetriever retriever = WikipediaRetriever() Usage: .. code-block:: python docs = retriever.invoke("TOKYO GHOUL") print(docs[0].page_content[:100]) .. code-block:: none Tokyo Ghoul (Japanese: 東京喰種(トーキョーグール), Hepburn: Tōkyō Gūru) is a Japanese dark fantasy Use within a chain: .. code-block:: python from langchain_core.output_parsers import StrOutputParser from langchain_core.prompts import ChatPromptTemplate from langchain_core.runnables import RunnablePassthrough from langchain_openai import ChatOpenAI prompt = ChatPromptTemplate.from_template( \"\"\"Answer the question based only on the context provided. Context: {context} Question: {question}\"\"\" ) llm = ChatOpenAI(model="gpt-3.5-turbo-0125") def format_docs(docs): return "\\n\\n".join(doc.page_content for doc in docs) chain = ( {"context": retriever | format_docs, "question": RunnablePassthrough()} | prompt | llm | StrOutputParser() ) chain.invoke( "Who is the main character in `Tokyo Ghoul` and does he transform into a ghoul?" ) .. code-block:: none 'The main character in Tokyo Ghoul is Ken Kaneki, who transforms into a ghoul after receiving an organ transplant from a ghoul named Rize.' """ # noqa: E501 def _get_relevant_documents( self, query: str, *, run_manager: CallbackManagerForRetrieverRun ) -> List[Document]: return self.load(query=query)