Source code for langchain.utilities.wikipedia
"""Util that calls Wikipedia."""
import logging
from typing import Any, Dict, List, Optional
from langchain.pydantic_v1 import BaseModel, root_validator
from langchain.schema import Document
logger = logging.getLogger(__name__)
WIKIPEDIA_MAX_QUERY_LENGTH = 300
[docs]class WikipediaAPIWrapper(BaseModel):
    """Wrapper around WikipediaAPI.
    To use, you should have the ``wikipedia`` python package installed.
    This wrapper will use the Wikipedia API to conduct searches and
    fetch page summaries. By default, it will return the page summaries
    of the top-k results.
    It limits the Document content by doc_content_chars_max.
    """
    wiki_client: Any  #: :meta private:
    top_k_results: int = 3
    lang: str = "en"
    load_all_available_meta: bool = False
    doc_content_chars_max: int = 4000
    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that the python package exists in environment."""
        try:
            import wikipedia
            wikipedia.set_lang(values["lang"])
            values["wiki_client"] = wikipedia
        except ImportError:
            raise ImportError(
                "Could not import wikipedia python package. "
                "Please install it with `pip install wikipedia`."
            )
        return values
[docs]    def run(self, query: str) -> str:
        """Run Wikipedia search and get page summaries."""
        page_titles = self.wiki_client.search(query[:WIKIPEDIA_MAX_QUERY_LENGTH])
        summaries = []
        for page_title in page_titles[: self.top_k_results]:
            if wiki_page := self._fetch_page(page_title):