cascadiavspyquery
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.
PyQuery is a Python library for working with XML and HTML documents. It is similar to BeautifulSoup and is often used as a drop-in replacement for it.
PyQuery is inspired by javascript's jQuery and uses similar API allowing selecting of HTML nodes through CSS selectors. This makes it easy for developers who are already familiar with jQuery to use PyQuery in Python.
Unlike jQuery, PyQuery doesn't support XPath selectors and relies entirely on CSS selectors though offers similar HTML parsing features like selection of HTML elements, their attributes and text as well as html tree modification.
PyQuery also comes with a http client (through requests) so it can load and parse web URLs by itself.
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 pyquery import PyQuery as pq
# 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>
"""
doc = pq(html)
# we can use CSS selectors:
print(doc('#product .price').text())
"$10"
# it's also possible to modify HTML tree in various ways:
# insert text into selected element:
print(doc('h1').append('<span>discounted</span>'))
"<h1>Product Title<span>discounted</span></h1>"
# or remove elements
doc('p').remove()
print(doc('#product').html())
"""
<h1>Product Title<span>discounted</span></h1>
<span class="price">$10</span>
"""
# pyquery can also retrieve web documents using requests:
doc = pq(url='http://httpbin.org/html', headers={"User-Agent": "webscraping.fyi"})
print(doc('h1').html())