Web Scraping with Scala & ChatGPT

Sep 25, 2023 ยท 4 min read

Scala is a great language for web scraping thanks to its functional programming features and concise syntax. ChatGPT is an AI assistant that can provide explanations and generate code for scraping tasks. This article covers web scraping in Scala with help from ChatGPT.

Setting Up Scala for Web Scraping

You'll need the JVM installed along with these libraries:

// Scalaj for HTTP requests
libraryDependencies += "org.scalaj" %% "scalaj-http" % "2.4.2"

// Jsoup for HTML parsing
libraryDependencies += "org.jsoup" % "jsoup" % "1.13.1"

// CSV library for CSV parsing
libraryDependencies += "com.github.tototoshi" %% "scala-csv" % "1.3.6"

Introduction to Web Scraping in Scala

Web scraping involves sending HTTP requests to websites and extracting data from the HTML, JSON or XML responses. Useful Scala libraries:

  • Scalaj - HTTP client for requests
  • Jsoup - Java HTML parser with CSS selectors
  • Rucola - High-level web crawling/scraping framework
  • Typical web scraping workflow:

  • Send HTTP request to download a page
  • Parse response and extract relevant data
  • Store scraped data
  • Repeat for other pages
  • Using ChatGPT for Web Scraping Help

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

    Getting Explanations

    Ask ChatGPT to explain web scraping concepts or specifics:

  • How to use Jsoup to extract text from paragraph tags
  • Strategies for scraping content spread across pagination
  • Generating Code Snippets

    Give a description of what you want to scrape and have ChatGPT provide starter Scala code:

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

    Improving Prompts

    Ask ChatGPT to suggest ways to improve your prompt if it doesn't provide helpful responses.

    Asking Follow-up Questions

    Chat with ChatGPT to get explanations for any other questions you have.

    Explaining Errors

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

    Web Scraping Example Using ChatGPT

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

    Goal

    Extract the chronology table from:

    https://en.wikipedia.org/wiki/Chronology_of_the_universe

    Step 1: Download page

    ChatGPT: Scala code to download this page:
    <https://en.wikipedia.org/wiki/Chronology_of_the_universe>
    
    // ChatGPT provides this code
    import scalaj.http._
    
    val response = Http("<https://en.wikipedia.org/wiki/Chronology_of_the_universe>").asString
    

    Step 2: Inspect HTML, table has class wikitable

    Step 3: Extract table data to CSV

    ChatGPT: Scala code to extract wikitable table to CSV
    
    // ChatGPT provides this code
    import org.jsoup.Jsoup
    import scala.collection.JavaConverters._
    
    val doc = Jsoup.parse(response.body)
    val table = doc.select("table.wikitable").first
    
    // Extract headers
    val headers = table.select("thead th").map(_.text()).toSeq
    
    // Extract rows
    val rows = table.select("tbody tr").map(row =>
      row.select("td").map(_.text()).toSeq
    ).toSeq
    
    // Write rows to CSV
    // ...
    

    This demonstrates using ChatGPT to get Scala scraping code quickly.

    Conclusion

    Key points:

  • Scala provides functional programming for web scraping
  • ChatGPT can explain concepts and provide Scala code
  • Inspect HTML to understand how to extract data
  • Follow best practices like throttling requests, randomizing user agents
  • Web scraping allows gathering data from websites at scale with Scala
  • ChatGPT + Scala is a powerful combo for building 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:

    import scalaj.http._
    
    Http("<https://api.proxiesapi.com/?url=example.com&key=XXX>").asString
    

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

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