Add automated daily price scraper for PC component pricing

[Copilot]

Describe the Pull Request

Implements automated price scraping from PCPartPicker (aggregates Newegg, Amazon, Best Buy) to keep all 75 PC build markdown files current. Runs daily via GitHub Actions at 2 AM UTC.

Implementation

• scraper.py (370 lines): Parses markdown files, extracts PCPartPicker URLs, scrapes prices, updates tables with current pricing and retailer info. Includes rate limiting (2s), error handling, whitelisted domain validation, and flexible HTML parsing to handle PCPartPicker's versioned class names (e.g., td__component-2025). Supports debug mode via DEBUG environment variable.

• .github/workflows/update-prices.yml: Scheduled workflow with manual trigger option and debug mode checkbox. Auto-commits price changes using GitHub Actions bot.

• requirements.txt: beautifulsoup4, requests, lxml (all verified secure, zero vulnerabilities)

• SCRAPER_README.md: Architecture, usage, troubleshooting, maintenance guide

• .gitignore: Python artifacts excluded

• README.md: Feature documentation added

Technical Approach

Uses PCPartPicker as data source rather than scraping individual retailers directly - more reliable and maintainable since PCPartPicker already aggregates multi-retailer pricing. Updates prices in-place preserving historical "Print Price" columns.

The scraper uses flexible class name matching to handle PCPartPicker's evolving HTML structure, supporting both legacy class names and versioned suffixes (e.g., -2025). Implements 4 fallback strategies to locate the parts table, ensuring robustness against HTML changes.

# Example: Extract and update from PCPartPicker
url = scraper.extract_pcpartpicker_url(markdown_content)
prices = scraper.scrape_build_prices(url)  # Returns {product: (price, retailer)}
scraper.update_markdown_file(filepath, prices)  # Updates table cells

Expected Behavior

PC component prices across all markdown files update automatically daily. Manual workflow trigger available from Actions tab with optional debug mode. Changes auto-committed when prices update. The scraper correctly handles PCPartPicker's current HTML structure with versioned class names and extracts prices from the new link format.

Fixes the Following Issues

Addresses requirement for automated daily price updates from major retailers (Newegg, BestBuy, Amazon) with GitHub Actions integration. Resolves HTML parsing issues caused by PCPartPicker's updated structure with versioned class suffixes.

Screenshots

N/A - Backend automation only

Desktop Developed On (please complete the following information):

• OS: Linux (Ubuntu)
• Browser: N/A
• Browser Version: N/A

Additional Context

Security: CodeQL verified, proper URL parsing with domain whitelist. All dependencies scanned clean. Rate-limited requests prevent server abuse.

The scraper has been updated to handle PCPartPicker's new HTML structure (2025 format) which uses versioned class names. It now:

• Uses flexible class matching with lambda functions to handle any version suffix
• Extracts prices from <a class="pp_async_mr"> links
• Gets retailer information from td__where column with image alt text
• Implements multiple fallback strategies for table detection
• Supports debug mode for troubleshooting (saves HTML output when enabled)
• Maintains backward compatibility with older HTML structures

Testing confirms successful parsing of the new HTML format while maintaining compatibility with legacy structures.

Original prompt

This website creates lists of computer parts with prices listed on the website. Create a web scraper that will grab the price for each of the computer parts from retailers like Newegg, BestBuy, and Amazon. This scraper should be run once a day as a GitHub Action, and it should update the website price displays.

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[willtheorangeguy]

@copilot I get the following log output, which makes it look like the scraper is not working correctly: 2025-11-18 17:50:04,771 - INFO - Scraping prices from: https://ca.pcpartpicker.com/list/4n3mNc
2025-11-18 17:50:07,461 - WARNING - Could not find parts table on https://ca.pcpartpicker.com/list/4n3mNc
2025-11-18 17:50:07,461 - WARNING - No prices scraped for Budget.md

[Copilot]

@copilot I get the following log output, which makes it look like the scraper is not working correctly: 2025-11-18 17:50:04,771 - INFO - Scraping prices from: https://ca.pcpartpicker.com/list/4n3mNc
2...

Fixed in commit 0035b97. PCPartPicker updated their HTML structure to use versioned class names (e.g., td__component-2025, td__name-2025, td__price-2025).

The scraper now:

• Uses flexible class matching to handle versioned suffixes
• Extracts prices from the new <a class="pp_async_mr"> link structure
• Gets retailer info from the td__where column with image alt text
• Includes 4 fallback strategies to find the parts table
• Supports debug mode via DEBUG=1 environment variable or workflow input checkbox

Tested with the actual PCPartPicker HTML structure you provided - now successfully parses products, prices, and retailers.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• ca.pcpartpicker.com
  • Triggering command: python3 /tmp/test_pcpartpicker_structure.py (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)