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#

# Source code for langchain.document_loaders.web_base

    """Web base loader class."""
    import asyncio
    import logging
    import warnings
    from typing import Any, List, Optional, Union

    import aiohttp
    import requests

    from langchain.docstore.document import Document
    from langchain.document_loaders.base import BaseLoader

    logger = logging.getLogger(__name__)

    default_header_template = {
        "User-Agent": "",
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*"
        ";q=0.8",
        "Accept-Language": "en-US,en;q=0.5",
        "Referer": "https://www.google.com/",
        "DNT": "1",
        "Connection": "keep-alive",
        "Upgrade-Insecure-Requests": "1",
    }

    def _build_metadata(soup: Any, url: str) -> dict:
        """Build metadata from BeautifulSoup output."""
        metadata = {"source": url}
        if title := soup.find("title"):
            metadata["title"] = title.get_text()
        if description := soup.find("meta", attrs={"name": "description"}):
            metadata["description"] = description.get("content", None)
        if html := soup.find("html"):
            metadata["language"] = html.get("lang", None)
        return metadata

    class WebBaseLoader(BaseLoader):
        """Loader that uses urllib and beautiful soup to load webpages."""

        web_paths: List[str]

        requests_per_second: int = 2
        """Max number of concurrent requests to make."""

        default_parser: str = "html.parser"
        """Default parser to use for BeautifulSoup."""

        def __init__(
            self, web_path: Union[str, List[str]], header_template: Optional[dict] = None
        ):
            """Initialize with webpage path."""

            # TODO: Deprecate web_path in favor of web_paths, and remove this
            # left like this because there are a number of loaders that expect single
            # urls
            if isinstance(web_path, str):
                self.web_paths = [web_path]
            elif isinstance(web_path, List):
                self.web_paths = web_path

            self.session = requests.Session()
            try:
                import bs4  # noqa:F401
            except ImportError:
                raise ValueError(
                    "bs4 package not found, please install it with " "`pip install bs4`"
                )

            try:
                from fake_useragent import UserAgent

                headers = header_template or default_header_template
                headers["User-Agent"] = UserAgent().random
                self.session.headers = dict(headers)
            except ImportError:
                logger.info(
                    "fake_useragent not found, using default user agent."
                    "To get a realistic header for requests, `pip install fake_useragent`."
                )

        @property
        def web_path(self) -> str:
            if len(self.web_paths) > 1:
                raise ValueError("Multiple webpaths found.")
            return self.web_paths[0]

        async def _fetch(
            self, url: str, retries: int = 3, cooldown: int = 2, backoff: float = 1.5
        ) -> str:
            async with aiohttp.ClientSession() as session:
                for i in range(retries):
                    try:
                        async with session.get(
                            url, headers=self.session.headers
                        ) as response:
                            return await response.text()
                    except aiohttp.ClientConnectionError as e:
                        if i == retries - 1:
                            raise
                        else:
                            logger.warning(
                                f"Error fetching {url} with attempt "
                                f"{i + 1}/{retries}: {e}. Retrying..."
                            )
                            await asyncio.sleep(cooldown * backoff**i)
            raise ValueError("retry count exceeded")

        async def _fetch_with_rate_limit(
            self, url: str, semaphore: asyncio.Semaphore
        ) -> str:
            async with semaphore:
                return await self._fetch(url)

        async def fetch_all(self, urls: List[str]) -> Any:
            """Fetch all urls concurrently with rate limiting."""
            semaphore = asyncio.Semaphore(self.requests_per_second)
            tasks = []
            for url in urls:
                task = asyncio.ensure_future(self._fetch_with_rate_limit(url, semaphore))
                tasks.append(task)
            try:
                from tqdm.asyncio import tqdm_asyncio

                return await tqdm_asyncio.gather(
                    *tasks, desc="Fetching pages", ascii=True, mininterval=1
                )
            except ImportError:
                warnings.warn("For better logging of progress, `pip install tqdm`")
                return await asyncio.gather(*tasks)

        @staticmethod
        def _check_parser(parser: str) -> None:
            """Check that parser is valid for bs4."""
            valid_parsers = ["html.parser", "lxml", "xml", "lxml-xml", "html5lib"]
            if parser not in valid_parsers:
                raise ValueError(
                    "`parser` must be one of " + ", ".join(valid_parsers) + "."
                )

        def scrape_all(self, urls: List[str], parser: Union[str, None] = None) -> List[Any]:
            """Fetch all urls, then return soups for all results."""
            from bs4 import BeautifulSoup

            results = asyncio.run(self.fetch_all(urls))
            final_results = []
            for i, result in enumerate(results):
                url = urls[i]
                if parser is None:
                    if url.endswith(".xml"):
                        parser = "xml"
                    else:
                        parser = self.default_parser
                    self._check_parser(parser)
                final_results.append(BeautifulSoup(result, parser))

            return final_results

        def _scrape(self, url: str, parser: Union[str, None] = None) -> Any:
            from bs4 import BeautifulSoup

            if parser is None:
                if url.endswith(".xml"):
                    parser = "xml"
                else:
                    parser = self.default_parser

            self._check_parser(parser)

            html_doc = self.session.get(url)
            return BeautifulSoup(html_doc.text, parser)

        def scrape(self, parser: Union[str, None] = None) -> Any:
            """Scrape data from webpage and return it in BeautifulSoup format."""

            if parser is None:
                parser = self.default_parser

            return self._scrape(self.web_path, parser)

        def load(self) -> List[Document]:
            """Load text from the url(s) in web_path."""
            docs = []
            for path in self.web_paths:
                soup = self._scrape(path)
                text = soup.get_text()
                metadata = _build_metadata(soup, path)
                docs.append(Document(page_content=text, metadata=metadata))

            return docs

        def aload(self) -> List[Document]:
            """Load text from the urls in web_path async into Documents."""

            results = self.scrape_all(self.web_paths)
            docs = []
            for i in range(len(results)):
                soup = results[i]
                text = soup.get_text()
                metadata = _build_metadata(soup, self.web_paths[i])
                docs.append(Document(page_content=text, metadata=metadata))

            return docs