mirror of
https://github.com/hwchase17/langchain
synced 2024-11-08 07:10:35 +00:00
81 lines
2.4 KiB
Python
81 lines
2.4 KiB
Python
import asyncio
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import logging
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from typing import Iterator, List
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from langchain_core.documents import Document
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from langchain_community.document_loaders.base import BaseLoader
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logger = logging.getLogger(__name__)
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class AsyncChromiumLoader(BaseLoader):
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"""Scrape HTML pages from URLs using a
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headless instance of the Chromium."""
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def __init__(
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self,
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urls: List[str],
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):
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"""
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Initialize the loader with a list of URL paths.
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Args:
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urls (List[str]): A list of URLs to scrape content from.
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Raises:
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ImportError: If the required 'playwright' package is not installed.
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"""
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self.urls = urls
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try:
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import playwright # noqa: F401
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except ImportError:
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raise ImportError(
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"playwright is required for AsyncChromiumLoader. "
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"Please install it with `pip install playwright`."
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)
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async def ascrape_playwright(self, url: str) -> str:
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"""
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Asynchronously scrape the content of a given URL using Playwright's async API.
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Args:
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url (str): The URL to scrape.
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Returns:
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str: The scraped HTML content or an error message if an exception occurs.
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"""
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from playwright.async_api import async_playwright
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logger.info("Starting scraping...")
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results = ""
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async with async_playwright() as p:
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browser = await p.chromium.launch(headless=True)
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try:
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page = await browser.new_page()
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await page.goto(url)
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results = await page.content() # Simply get the HTML content
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logger.info("Content scraped")
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except Exception as e:
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results = f"Error: {e}"
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await browser.close()
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return results
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def lazy_load(self) -> Iterator[Document]:
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"""
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Lazily load text content from the provided URLs.
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This method yields Documents one at a time as they're scraped,
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instead of waiting to scrape all URLs before returning.
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Yields:
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Document: The scraped content encapsulated within a Document object.
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"""
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for url in self.urls:
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html_content = asyncio.run(self.ascrape_playwright(url))
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metadata = {"source": url}
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yield Document(page_content=html_content, metadata=metadata)
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