"""Loader that uses Playwright to load a page, then uses unstructured to parse html."""
import logging
from abc import ABC, abstractmethod
from typing import TYPE_CHECKING, AsyncIterator, Dict, Iterator, List, Optional
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseLoader
if TYPE_CHECKING:
from playwright.async_api import Browser as AsyncBrowser
from playwright.async_api import Page as AsyncPage
from playwright.async_api import Response as AsyncResponse
from playwright.sync_api import Browser, Page, Response
logger = logging.getLogger(__name__)
[docs]class PlaywrightEvaluator(ABC):
"""Abstract base class for all evaluators.
Each evaluator should take a page, a browser instance, and a response
object, process the page as necessary, and return the resulting text.
"""
[docs] @abstractmethod
def evaluate(self, page: "Page", browser: "Browser", response: "Response") -> str:
"""Synchronously process the page and return the resulting text.
Args:
page: The page to process.
browser: The browser instance.
response: The response from page.goto().
Returns:
text: The text content of the page.
"""
pass
[docs] @abstractmethod
async def evaluate_async(
self, page: "AsyncPage", browser: "AsyncBrowser", response: "AsyncResponse"
) -> str:
"""Asynchronously process the page and return the resulting text.
Args:
page: The page to process.
browser: The browser instance.
response: The response from page.goto().
Returns:
text: The text content of the page.
"""
pass
[docs]class UnstructuredHtmlEvaluator(PlaywrightEvaluator):
"""Evaluate the page HTML content using the `unstructured` library."""
[docs] def __init__(self, remove_selectors: Optional[List[str]] = None):
"""Initialize UnstructuredHtmlEvaluator."""
try:
import unstructured # noqa:F401
except ImportError:
raise ImportError(
"unstructured package not found, please install it with "
"`pip install unstructured`"
)
self.remove_selectors = remove_selectors
[docs] def evaluate(self, page: "Page", browser: "Browser", response: "Response") -> str:
"""Synchronously process the HTML content of the page."""
from unstructured.partition.html import partition_html
for selector in self.remove_selectors or []:
elements = page.locator(selector).all()
for element in elements:
if element.is_visible():
element.evaluate("element => element.remove()")
page_source = page.content()
elements = partition_html(text=page_source)
return "\n\n".join([str(el) for el in elements])
[docs] async def evaluate_async(
self, page: "AsyncPage", browser: "AsyncBrowser", response: "AsyncResponse"
) -> str:
"""Asynchronously process the HTML content of the page."""
from unstructured.partition.html import partition_html
for selector in self.remove_selectors or []:
elements = await page.locator(selector).all()
for element in elements:
if await element.is_visible():
await element.evaluate("element => element.remove()")
page_source = await page.content()
elements = partition_html(text=page_source)
return "\n\n".join([str(el) for el in elements])
[docs]class PlaywrightURLLoader(BaseLoader):
"""Load `HTML` pages with `Playwright` and parse with `Unstructured`.
This is useful for loading pages that require javascript to render.
Attributes:
urls (List[str]): List of URLs to load.
continue_on_failure (bool): If True, continue loading other URLs on failure.
headless (bool): If True, the browser will run in headless mode.
proxy (Optional[Dict[str, str]]): If set, the browser will access URLs
through the specified proxy.
Example:
.. code-block:: python
from langchain_community.document_loaders import PlaywrightURLLoader
urls = ["https://api.ipify.org/?format=json",]
proxy={
"server": "https://xx.xx.xx:15818", # https://<host>:<port>
"username": "username",
"password": "password"
}
loader = PlaywrightURLLoader(urls, proxy=proxy)
data = loader.load()
"""
[docs] def __init__(
self,
urls: List[str],
continue_on_failure: bool = True,
headless: bool = True,
remove_selectors: Optional[List[str]] = None,
evaluator: Optional[PlaywrightEvaluator] = None,
proxy: Optional[Dict[str, str]] = None,
):
"""Load a list of URLs using Playwright."""
try:
import playwright # noqa:F401
except ImportError:
raise ImportError(
"playwright package not found, please install it with "
"`pip install playwright`"
)
self.urls = urls
self.continue_on_failure = continue_on_failure
self.headless = headless
self.proxy = proxy
if remove_selectors and evaluator:
raise ValueError(
"`remove_selectors` and `evaluator` cannot be both not None"
)
# Use the provided evaluator, if any, otherwise, use the default.
self.evaluator = evaluator or UnstructuredHtmlEvaluator(remove_selectors)
[docs] def lazy_load(self) -> Iterator[Document]:
"""Load the specified URLs using Playwright and create Document instances.
Returns:
A list of Document instances with loaded content.
"""
from playwright.sync_api import sync_playwright
with sync_playwright() as p:
browser = p.chromium.launch(headless=self.headless, proxy=self.proxy)
for url in self.urls:
try:
page = browser.new_page()
response = page.goto(url)
if response is None:
raise ValueError(f"page.goto() returned None for url {url}")
text = self.evaluator.evaluate(page, browser, response)
metadata = {"source": url}
yield Document(page_content=text, metadata=metadata)
except Exception as e:
if self.continue_on_failure:
logger.error(
f"Error fetching or processing {url}, exception: {e}"
)
else:
raise e
browser.close()
[docs] async def aload(self) -> List[Document]:
"""Load the specified URLs with Playwright and create Documents asynchronously.
Use this function when in a jupyter notebook environment.
Returns:
A list of Document instances with loaded content.
"""
return [doc async for doc in self.alazy_load()]
[docs] async def alazy_load(self) -> AsyncIterator[Document]:
"""Load the specified URLs with Playwright and create Documents asynchronously.
Use this function when in a jupyter notebook environment.
Returns:
A list of Document instances with loaded content.
"""
from playwright.async_api import async_playwright
async with async_playwright() as p:
browser = await p.chromium.launch(headless=self.headless, proxy=self.proxy)
for url in self.urls:
try:
page = await browser.new_page()
response = await page.goto(url)
if response is None:
raise ValueError(f"page.goto() returned None for url {url}")
text = await self.evaluator.evaluate_async(page, browser, response)
metadata = {"source": url}
yield Document(page_content=text, metadata=metadata)
except Exception as e:
if self.continue_on_failure:
logger.error(
f"Error fetching or processing {url}, exception: {e}"
)
else:
raise e
await browser.close()
