Install Requests-HTML in Python for Web Parsing

Web parsing is a key skill for developers. It helps extract data from websites. Python makes it easy with libraries like Requests-HTML.

This guide will show you how to install and use Requests-HTML. You'll learn to scrape web pages efficiently.

What is Requests-HTML?

Requests-HTML is a Python library. It simplifies web scraping and parsing. It combines Requests and HTML parsing in one package.

It supports JavaScript rendering. This makes it great for modern websites. You can also handle sessions and cookies easily.

Prerequisites

Before installing Requests-HTML, you need Python. Python 3.6 or higher is recommended. Check your Python version with:

 
import sys
print(sys.version)

You should also have pip installed. Pip is Python's package manager. It comes with most Python installations.

Installing Requests-HTML

Installing Requests-HTML is simple. Use pip in your terminal or command prompt:

pip install requests-html

This will install Requests-HTML and its dependencies. The process may take a few seconds.

If you encounter issues, try upgrading pip first. Run pip install --upgrade pip before installing Requests-HTML.

Basic Usage of Requests-HTML

After installation, you can start using Requests-HTML. First, import it in your Python script:

 
from requests_html import HTMLSession

Create a session to make requests:

 
session = HTMLSession()
response = session.get('https://example.com')

This fetches the webpage. You can now parse the HTML content.

Parsing HTML with Requests-HTML

Requests-HTML provides easy HTML parsing. Use the html property to access parsed content:

 
links = response.html.links
print(links)

This prints all links on the page. You can also find elements using CSS selectors:

 
title = response.html.find('title', first=True)
print(title.text)

This finds the page title and prints its text.

Handling JavaScript Pages

Some pages load content with JavaScript. Requests-HTML can render JavaScript:

 
response.html.render()

This may take a few seconds. After rendering, you can parse the full content.

Practical Example

Let's scrape a sample page. We'll extract headlines from a news site:

 
from requests_html import HTMLSession

session = HTMLSession()
response = session.get('https://news.example.com')
response.html.render()

headlines = response.html.find('.headline')
for headline in headlines:
    print(headline.text)

This code renders the page. Then it finds all elements with class 'headline'. Finally, it prints each headline text.

Error Handling

Always handle errors in web scraping. Requests-HTML may encounter connection issues:

 
try:
    response = session.get('https://example.com')
    response.raise_for_status()
except Exception as e:
    print(f"Error: {e}")

This catches connection errors. It prevents your script from crashing.

Advanced Features

Requests-HTML offers more advanced features. You can:

• Handle forms and submissions
• Manage cookies and sessions
• Work with asynchronous requests

For complex workflows, consider Luigi or Dask.

Conclusion

Requests-HTML is powerful for web parsing. It's easy to install and use. You can scrape both static and JavaScript pages.

Remember to scrape responsibly. Check a website's robots.txt before scraping. For big data projects, PySpark might be useful.

Now you're ready to start web parsing with Python and Requests-HTML. Happy scraping!