parselvsnokogiri
parsel is a library for parsing HTML and XML using selectors, similar to beautifulsoup. It is built on top of the lxml library and allows for easy extraction of data from HTML and XML files using selectors, similar to how you would use CSS selectors in web development. It is a light-weight library which is specifically designed for web scraping and parsing, so it is more efficient and faster than beautifulsoup in some use cases.
Some of the key features of parsel include:
- CSS selector & XPath selector support:
Two most common html parsing path languages are both supported in parsel. This allows selecting attributes, tags, text and complex matching rules that use regular expressions or XPath functions. - Modifying data:
parselallows you to modify the contents of an element, remove elements or add new elements to a document. - Support for both HTML and XML:
parselsupports both HTML and XML documents and you can use the same selectors for both formats.
It is easy to use and less verbose than beautifulsoup, so it's quite popular among the developers who are working with Web scraping projects and parse data from large volume of web pages.
Nokogiri is a Ruby gem that provides a simple and powerful way to parse and search XML and HTML documents. It is built on top of the underlying C library libxml2, which is known for its speed and reliability.
Nokogiri provides a simple and intuitive API for parsing and searching XML and HTML documents, and it is widely used in the Ruby ecosystem for web scraping and data extraction.
One of the main features of Nokogiri is its ability to search and navigate through XML and HTML documents using a CSS or XPath selectors.
Nokogiri also provides a variety of other features that can simplify the process of working with XML and HTML documents. It can automatically handle character encodings and normalize documents, it can parse and search large documents with low memory usage, and it can validate documents against a DTD or schema.
Highlights
Example Use
from parsel import Selector
# this is our HTML page:
html = """
<head>
<title>Hello World!</title>
</head>
<body>
<div id="product">
<h1>Product Title</h1>
<p>paragraph 1</p>
<p>paragraph2</p>
<span class="price">$10</span>
</div>
</body>
"""
selector = Selector(html)
# we can use CSS selectors:
selector.css("#product .price::text").get()
"$10"
# or XPath:
selector.xpath('//span[@class="price"]').get()
"$10"
# or get all matching elements:
print(selector.css("#product p::text").getall())
["paragraph 1", "paragraph2"]
# parsel also comes with utility methods like regular expression parsing:
selector.xpath('//span[@class="price"]').re("\d+")
["10"]
require 'nokogiri'
html_string = '<html><head><title>Page Title</title></head><body><h1 class="header-class">Hello World!</h1><p>This is a sample webpage.</p></body></html>'
# Parse the HTML string
doc = Nokogiri::HTML(html_string)
# Extract the class attribute of h1 tag using CSS selector
h1_class = doc.css("h1")[0]['class']
# or XPath
h1_class = doc.xpath("//h1")[0]['class']
puts "H1 class: #{h1_class}"