Master HTML parsing in Python. Learn to parse HTML documents with html.parser, lxml, and html5lib. Understand DOM manipulation, parsing strategies, and choose the right parser for your needs.
HTML parsing is the process of analyzing HTML documents and extracting their structure and content. It's the foundation of web scraping and data extraction.
HTML parsing converts raw HTML text into a structured format (usually a tree) that you can navigate and query programmatically. Instead of using string manipulation or regex, parsers understand HTML's nested structure.
HTML documents are tree-structured:
<html>
<head>
<title>Page Title</title>
</head>
<body>
<h1>Heading</h1>
<p class="intro">Paragraph text</p>
<div id="content">
<a href="/page">Link</a>
</div>
</body>
</html>
Key concepts:
<div>, <p>, <a>class="intro", id="content", href="/page"Python offers multiple HTML parsers:
| Parser | Speed | Leniency | Installation |
|---|---|---|---|
| html.parser | Medium | Good | Built-in |
| lxml | Fast | Very good | pip install lxml |
| html5lib | Slow | Excellent | pip install html5lib |
All three work with libraries like Beautiful Soup, or can be used directly.