Web Scraping with Ruby & ChatGPT

Sep 25, 2023 ยท 3 min read

Web scraping involves extracting data from websites programmatically. Ruby is a great language for scraping thanks to libraries like Nokogiri, Mechanize, and Anemone. ChatGPT is an AI assistant that can provide code snippets and explanations for web scraping tasks. This article covers web scraping in Ruby and how ChatGPT can help.

Setting Up a Ruby Environment

You'll need Ruby installed along with gems like Nokogiri, Anemone, and Mechanize:

# Nokogiri for HTML parsing
gem install nokogiri

# Anemone for crawling
gem install anemone

# Mechanize for browser automation
gem install mechanize

Introduction to Web Scraping in Ruby

Web scraping is done by sending HTTP requests to websites, then extracting data from the HTML, JSON or XML response. Useful Ruby libs:

  • Nokogiri - HTML/XML parsing and searching DOM
  • Anemone - Web spidering/crawling
  • Mechanize - Automating interaction with websites
  • Basic scraping workflow:

  • Fetch page with HTTP request
  • Parse response and extract data
  • Store scraped data
  • Repeat for other pages
  • ChatGPT for Web Scraping Help

    ChatGPT is an AI assistant created by OpenAI to be helpful, harmless, and honest. It can provide explanations and generate code snippets for web scraping:

    Generating Explanations

    Ask ChatGPT to explain web scraping concepts/specifics:

  • How to use Nokogiri to extract text from all paragraphs
  • Strategies for scraping content across pagination
  • Writing Code Snippets

    Provide a description of what you want to scrape and have ChatGPT generate starter Ruby code:

  • Scrape product listings into a CSV file
  • Parse date strings into DateTime when extracting dates
  • Validate any code before using.

    Improving Prompts

    Ask ChatGPT to suggest improvements if it doesn't provide helpful responses.

    Asking Follow-up Questions

    Chat with ChatGPT to get explanations for additional questions.

    Explaining Errors

    Share any errors and ask ChatGPT to debug and explain the issue.

    Web Scraping Example Using ChatGPT

    Let's walk through scraping a Wikipedia page with ChatGPT's help.

    Goal

    Extract the chronology table from: https://en.wikipedia.org/wiki/Chronology_of_the_universe

    Step 1: Download page

    ChatGPT: Ruby code to download this page:
    <https://en.wikipedia.org/wiki/Chronology_of_the_universe>
    
    # ChatGPT provides this code
    require 'open-uri'
    
    url = '<https://en.wikipedia.org/wiki/Chronology_of_the_universe>'
    html = URI.open(url).read
    

    Step 2: Inspect HTML, table has class wikitable

    Step 3: Extract table data to CSV

    ChatGPT: Ruby code to extract wikitable table to CSV
    
    # ChatGPT provides this code
    require 'nokogiri'
    
    doc = Nokogiri::HTML(html)
    
    table = doc.at('table.wikitable')
    
    headers = table.xpath('.//tr[1]/th').map(&:text)
    rows = table.xpath('.//tr[position()>1]').map { |tr|
      tr.xpath('./td').map(&:text)
    }
    
    # save to CSV
    # ...
    

    This shows how we can quickly get Ruby scraping code from ChatGPT.

    Conclusion

    Key points:

  • Ruby has great libraries like Nokogiri, Mechanize for web scraping
  • ChatGPT can explain concepts and provide Ruby scraping code
  • Inspect HTML to understand how to extract the desired data
  • Follow best practices like throttling requests, randomizing user agents
  • Web scraping allows gathering data from websites at scale with Ruby
  • ChatGPT + Ruby is great for creating web scrapers.

    However, some limitations:

  • Handling anti-scraping measures like CAPTCHAs
  • Avoiding IP blocks when running locally
  • Rendering complex JavaScript pages
  • A more robust solution is using a web scraping API like Proxies API

    Proxies API provides:

  • Millions of proxy IPs to prevent blocks
  • Automated solving of CAPTCHAs
  • JavaScript rendering with headless browsing
  • Simple API instead of running your own scrapers
  • Easily scrape any site:

    require 'net/http'
    uri = URI("<https://api.proxiesapi.com/?url=example.com&key=XXX>")
    response = Net::HTTP.get(uri)
    

    Get started now with 1000 free API calls to supercharge your web scraping!

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