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cascadiavscssselect

BSD-2-Clause 1 1 675
58.1 thousand (month) Feb 20 2018 Start(6 years ago)
281 8 21 BSD
1.2.0(1 year, 5 months ago) Apr 14 2012 8.3 million (month)

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.

cssselect is a BSD-licensed Python library to parse CSS3 selectors and translate them to XPath 1.0 expressions.

XPath 1.0 expressions can be used in lxml or another XPath engine to find the matching elements in an XML or HTML document.

cssselect is used by other popular Python packages like parsel and scrapy but can also be used on it's own to generate valid XPath 1.0 expressions for parsing HTML and XML documents in other tools.

Note that because XPath selectors are more powerful than CSS selectors this translation is only possible one way. Converting XPath to CSS selectors is impractical and not supported by cssselect.

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 cssselect import GenericTranslator, SelectorError

translator = GenericTranslator()
try:
    expression = translator.css_to_xpath('div.content')
    print(expression)
    'descendant-or-self::div[@class and contains(concat(' ', normalize-space(@class), ' '), ' content ')]'
except SelectorError as e:
    print(f'Invalid selector {e}')

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