Playwright crawler

This example demonstrates how to use PlaywrightCrawler to recursively scrape the Hacker news website using headless Chromium and Playwright.

The PlaywrightCrawler manages the browser and page instances, simplifying the process of interacting with web pages. In the request handler, Playwright's API is used to extract data from each post on the page. Specifically, it retrieves the title, rank, and URL of each post. Additionally, the handler enqueues links to the next pages to ensure continuous scraping. This setup is ideal for scraping dynamic web pages where JavaScript execution is required to render the content.

A pre-navigation hook can be used to perform actions before navigating to the URL. This hook provides further flexibility in controlling environment and preparing for navigation.

import asyncio

from crawlee.crawlers import PlaywrightCrawler, PlaywrightCrawlingContext, PlaywrightPreNavCrawlingContext


async def main() -> None:
    crawler = PlaywrightCrawler(
        # Limit the crawl to max requests. Remove or increase it for crawling all links.
        max_requests_per_crawl=10,
        # Headless mode, set to False to see the browser in action.
        headless=False,
        # Browser types supported by Playwright.
        browser_type='chromium',
    )

    # Define the default request handler, which will be called for every request.
    # The handler receives a context parameter, providing various properties and
    # helper methods. Here are a few key ones we use for demonstration:
    # - request: an instance of the Request class containing details such as the URL
    #   being crawled and the HTTP method used.
    # - page: Playwright's Page object, which allows interaction with the web page
    #   (see https://playwright.dev/python/docs/api/class-page for more details).
    @crawler.router.default_handler
    async def request_handler(context: PlaywrightCrawlingContext) -> None:
        context.log.info(f'Processing {context.request.url} ...')

        # Extract data from the page using Playwright's API.
        posts = await context.page.query_selector_all('.athing')
        data = []

        for post in posts:
            # Get the HTML elements for the title and rank within each post.
            title_element = await post.query_selector('.title a')
            rank_element = await post.query_selector('.rank')

            # Extract the data we want from the elements.
            title = await title_element.inner_text() if title_element else None
            rank = await rank_element.inner_text() if rank_element else None
            href = await title_element.get_attribute('href') if title_element else None

            data.append({'title': title, 'rank': rank, 'href': href})

        # Push the extracted data to the default dataset. In local configuration,
        # the data will be stored as JSON files in ./storage/datasets/default.
        await context.push_data(data)

        # Find a link to the next page and enqueue it if it exists.
        await context.enqueue_links(selector='.morelink')

    # Define a hook that will be called each time before navigating to a new URL.
    # The hook receives a context parameter, providing access to the request and
    # browser page among other things. In this example, we log the URL being
    # navigated to.
    @crawler.pre_navigation_hook
    async def log_navigation_url(context: PlaywrightPreNavCrawlingContext) -> None:
        context.log.info(f'Navigating to {context.request.url} ...')

    # Run the crawler with the initial list of URLs.
    await crawler.run(['https://news.ycombinator.com/'])


if __name__ == '__main__':
    asyncio.run(main())