Web Scraping with Playwright: A Comprehensive Guide

Key takeaways:

1. Playwright is a powerful browser automation toolkit for web scraping, supporting cross-platform and cross-language operations.
2. Playwright allows for easy scraping of dynamic javascript-powered websites without requiring advanced web development knowledge.
3. Playwright supports multiple programming languages, including Python, and provides a more modern API compared to Selenium and Puppeteer.

Playwright for Web Scraping #

• Playwright is a browser automation toolkit that supports cross-platform and cross-language operations.
• It is primarily intended for website test suites but is also capable of general browser automation and web scraping.
• Playwright allows for automation of web headless browsers like Firefox or Chrome, enabling navigation, clicking buttons, writing text, and executing javascript.
• It is a great tool for web scraping as it allows scraping of dynamic javascript-powered websites without the need to reverse engineer their behavior.

Playwright vs Selenium vs Puppeteer #

• Playwright supports many programming languages, including Python, while Puppeteer is only available in Javascript.
• Playwright uses Chrome Devtools Protocol (CDP) and a more modern API, whereas Selenium is using webdriver protocol and a less modern API.
• Playwright supports both asynchronous and synchronous clients, whereas Selenium only supports a synchronous client and Puppeteer an asynchronous one.

Setting Up Playwright for Python #

• Playwright for Python can be installed through pip.
• It's best to use either Chrome or Firefox browsers for Playwright scraping as these are the most stable implementations and often are least likely to be blocked.

Playwright Basics for Web Scraping #

• To start, launch a browser and create a new browser tab.
• For web scraping, you need only a handful of Playwright features: navigation, button clicking, text input, javascript execution, and waiting for content to load.

Navigation and Waiting #

• Use the page.goto() function to navigate to any URL.
• For javascript-heavy websites, wait for a particular element to appear on the page to ensure that the page has loaded.

Parsing Data #

• Use the browser's HTML parsing capabilities through Playwright's locators feature.
• For more robust parsing, consider using traditional Python parsing libraries like parsel or beautifulsoup.

Clicking Buttons and Text Input #

• Use Playwright's locator functionality to interact with web components.
• For example, find the search box, input a search query, and click the search button or press Enter.

Scrolling and Infinite Pagination #

• To retrieve the rest of the results, continuously scroll to the last result visible on the page to trigger new page loads.
• Use Playwright's scroll_into_view_if_needed() function to scroll the last result into view.

Advanced Functions #

• Evaluate javascript code in the context of the current page for more complex web scraping targets.
• Intercept requests and responses to modify background requests or collect secret data from background responses.
• Block unnecessary resources to optimize bandwidth usage during web scraping.

Avoiding Blocking #

• While Playwright uses a real browser, it's still possible to determine whether it's controlled by a real user or automated by an automation toolkit.
• Consider using ScrapFly's alternative for javascript rendering and javascript scenario features to access thousands of custom web browsers that can render javascript-powered pages without being blocked.

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