Web Scraping

Determining Elements to Scrape from a Website

1. Inspect the Website Structure

Use browser developer tools (Right-click → Inspect) to:

  • Examine HTML structure (Elements tab)
  • Identify patterns in element classes/IDs
  • View network requests (Network tab)

2. Look for These Key Indicators


<!-- Unique identifiers -->
<div id="product-price-1234">$99.99</div>

<!-- Semantic class names -->

<span class="product-title">Item Name</span>

<!-- Structured data patterns -->
<ul class="search-results">
  <li class="result-item">...</li>
  <li class="result-item">...</li>
</ul>

<!-- Data attributes -->

<div data-product-id="5678" data-price="49.99"></div>

3. Common Targeting Strategies

Element Type Example Selector Use Case
CSS Classes .price Product prices
HTML Tags table Tabular data
Attributes [data-testid="price"] Test-identified elements
XPath //div[@class="header"] Complex hierarchies

4. Verification Techniques

  1. Test in browser console:
// CSS Selector
document.querySelectorAll('.product-card');

// XPath
$x('//div[contains(@class, "price")]')
  1. Check multiple pages to confirm consistency
  2. Monitor network requests for API endpoints

5. Tools to Help Identify Elements

  • SelectorGadget (Chrome extension)

  • XPath Helper (Browser extension)

  • Built-in browser copy selector:

    Right-click element → Copy → Copy selector/Copy XPath

Example Workflow

  1. Identify target data (e.g., product prices)
  2. Find common pattern in HTML structure
  3. Test selector in browser console
  4. Implement in code:
import requests
from bs4 import BeautifulSoup

response = requests.get('https://example.com/products')
soup = BeautifulSoup(response.text, 'html.parser')
prices = soup.select_all('span.price-value')  # CSS selector

Pro Tip: Start with broad selectors and gradually refine specificity to avoid missing similar elements.