mirror of
https://github.com/hwchase17/langchain
synced 2024-11-06 03:20:49 +00:00
92 lines
2.7 KiB
Python
92 lines
2.7 KiB
Python
|
import asyncio
|
||
|
import logging
|
||
|
from typing import Iterator, List
|
||
|
|
||
|
from langchain_core.documents import Document
|
||
|
|
||
|
from langchain_community.document_loaders.base import BaseLoader
|
||
|
|
||
|
logger = logging.getLogger(__name__)
|
||
|
|
||
|
|
||
|
class AsyncChromiumLoader(BaseLoader):
|
||
|
"""Scrape HTML pages from URLs using a
|
||
|
headless instance of the Chromium."""
|
||
|
|
||
|
def __init__(
|
||
|
self,
|
||
|
urls: List[str],
|
||
|
):
|
||
|
"""
|
||
|
Initialize the loader with a list of URL paths.
|
||
|
|
||
|
Args:
|
||
|
urls (List[str]): A list of URLs to scrape content from.
|
||
|
|
||
|
Raises:
|
||
|
ImportError: If the required 'playwright' package is not installed.
|
||
|
"""
|
||
|
self.urls = urls
|
||
|
|
||
|
try:
|
||
|
import playwright # noqa: F401
|
||
|
except ImportError:
|
||
|
raise ImportError(
|
||
|
"playwright is required for AsyncChromiumLoader. "
|
||
|
"Please install it with `pip install playwright`."
|
||
|
)
|
||
|
|
||
|
async def ascrape_playwright(self, url: str) -> str:
|
||
|
"""
|
||
|
Asynchronously scrape the content of a given URL using Playwright's async API.
|
||
|
|
||
|
Args:
|
||
|
url (str): The URL to scrape.
|
||
|
|
||
|
Returns:
|
||
|
str: The scraped HTML content or an error message if an exception occurs.
|
||
|
|
||
|
"""
|
||
|
from playwright.async_api import async_playwright
|
||
|
|
||
|
logger.info("Starting scraping...")
|
||
|
results = ""
|
||
|
async with async_playwright() as p:
|
||
|
browser = await p.chromium.launch(headless=True)
|
||
|
try:
|
||
|
page = await browser.new_page()
|
||
|
await page.goto(url)
|
||
|
results = await page.content() # Simply get the HTML content
|
||
|
logger.info("Content scraped")
|
||
|
except Exception as e:
|
||
|
results = f"Error: {e}"
|
||
|
await browser.close()
|
||
|
return results
|
||
|
|
||
|
def lazy_load(self) -> Iterator[Document]:
|
||
|
"""
|
||
|
Lazily load text content from the provided URLs.
|
||
|
|
||
|
This method yields Documents one at a time as they're scraped,
|
||
|
instead of waiting to scrape all URLs before returning.
|
||
|
|
||
|
Yields:
|
||
|
Document: The scraped content encapsulated within a Document object.
|
||
|
|
||
|
"""
|
||
|
for url in self.urls:
|
||
|
html_content = asyncio.run(self.ascrape_playwright(url))
|
||
|
metadata = {"source": url}
|
||
|
yield Document(page_content=html_content, metadata=metadata)
|
||
|
|
||
|
def load(self) -> List[Document]:
|
||
|
"""
|
||
|
Load and return all Documents from the provided URLs.
|
||
|
|
||
|
Returns:
|
||
|
List[Document]: A list of Document objects
|
||
|
containing the scraped content from each URL.
|
||
|
|
||
|
"""
|
||
|
return list(self.lazy_load())
|