71 posts tagged with "python"

Use Selenium Python's execute_script to access localStorage in the current document. Navigate to the intended origin first, pass keys and values as arguments, and include return when you need a value back in Python. If the application reads a preference at startup, set it before entering that application page or trigger its documented refresh afterward.

The last step matters for extraction. In our fixture, writing eu after the table loaded changed localStorage but left all four prices in USD. A wait that checked only the stored key would have accepted the wrong dataset. The examples below check storage, the application's request and the resulting records.

To change localStorage on an already loaded origin, use page.evaluate(). If the application reads that value during startup, install an origin-guarded context.add_init_script() before navigation, or create the context with the required storage_state.

That timing matters when scraping. In our catalog fixture, setting the region to eu after the table had loaded changed the stored value but left four US-priced rows on screen. A reload produced the intended EUR records. A successful storage write alone did not validate the data.

Puppeteer is a powerful Node.js library that provides a high-level API for controlling browsers through the DevTools Protocol. It is commonly used for testing, web scraping, and automating repetitive browser tasks. However, Puppeteer's default settings can trigger bot detection systems, especially in headless mode.

Which Playwright stealth library should you use? In this comparison, Patchright returned BrowserScan's Normal verdict when headed, while its headless user agent was flagged. Node's playwright-extra with the stealth plugin and the Firefox-based Camoufox returned Normal in both modes. Python playwright-stealth had no failed Sannysoft checks but still received BrowserScan's Navigator flag.

That difference is the useful result: changing a browser property, passing a diagnostic page and successfully retrieving your target are separate tests. Start with a reproducible control and keep the browser version, operating system and launch mode attached to every observation.

To set cookies with Playwright Python, call context.add_cookies() with a list of cookie dictionaries. Supply url, or a suitable domain and path, and set the cookies before navigating when the first request needs them. Use context.storage_state() when the workflow also depends on supported browser storage beyond cookies.

Restoring the cookie does not necessarily restore the dataset. In our catalog, cookies-only restoration kept member pricing but selected USD instead of EUR. A browser-associated API request made the same mistake when it omitted a region parameter that the page normally reads from local storage.

This guide shows the working state handoff and the failures around it. The fixture is self-authored and synthetic; it demonstrates specific mechanisms, not the probability that a real website will accept a restored login.

Approximately one in five websites targeted for scraping employ advanced anti-bot systems that can easily result in access being blocked. These systems, such as Cloudflare, DataDome, and PerimeterX, are designed to detect and block automated access, making it increasingly difficult for traditional scraping tools to function effectively.

To address these challenges, a variety of open-source libraries have emerged, each offering unique features and techniques to bypass these anti-bot mechanisms.

In the rapidly evolving landscape of web technologies, web scraping has emerged as a crucial tool for data extraction and analysis. As of 2024, two programming languages, JavaScript and Python, stand out as popular choices for developers engaging in web scraping tasks. Each language offers unique strengths and capabilities, making the decision between them a significant consideration for developers at all levels.

In the ever-evolving landscape of web automation and testing, two tools have consistently stood out: Playwright and Puppeteer. As of 2024, both have matured significantly, offering robust features for developers and testers alike. Both tools, developed by teams at Microsoft and Google respectively, offer robust solutions for automating browser tasks, but they cater to slightly different needs and preferences.

In the rapidly evolving landscape of web automation and testing, two open-source frameworks have emerged as leading tools: Playwright and Selenium. Both frameworks offer unique features and capabilities, making the choice between them a nuanced decision that depends on specific project requirements and team expertise.

In the ever-evolving landscape of web scraping, Python remains the language of choice for developers due to its simplicity, readability, and a robust ecosystem of libraries. Python offers a diverse array of HTTP clients that cater to various web scraping needs, from simple data extraction to complex, high-concurrency tasks.

This guide delves into the top Python HTTP clients, exploring their features, pros, cons, and providing code examples to get started.