cascadiavsparsel
cascadia is a library for Go that provides a CSS selector engine, allowing you to use CSS selectors to select elements from an HTML document.
It is built on top of the html package in the Go standard library, and provides a more efficient and powerful way to select elements from an HTML document.
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.
Highlights
Example Use
package main
import (
"fmt"
"github.com/andybalholm/cascadia"
"golang.org/x/net/html"
"strings"
)
func main() {
// Create an HTML string
html := `<html>
<body>
<div id="content">
<p>Hello, World!</p>
<a href="http://example.com">Example</a>
</div>
</body>
</html>`
// Parse the HTML string into a node tree
doc, err := html.Parse(strings.NewReader(html))
if err != nil {
fmt.Println("Error:", err)
return
}
// Compile the CSS selector
sel, err := cascadia.Compile("p")
if err != nil {
fmt.Println("Error:", err)
return
}
// Use the Selector.Match method to select elements from the document
matches := sel.Match(doc)
if len(matches) > 0 {
fmt.Println(matches[0].FirstChild.Data)
// > Hello, World!
}
}
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"]