cheeriovschompjs
cheerio is a popular JavaScript library that allows you to interact with and manipulate HTML and XML documents in a similar way to how you would with jQuery in a browser. It is a fast, flexible, and lean implementation of core jQuery designed specifically for the server.
One of the main benefits of using cheerio is that it allows you to use jQuery-like syntax to navigate and m anipulate the Document Object Model (DOM) of an HTML or XML document, making it easy to work with.
cheerio supports CSS selectors though not XPath.
chompjs can be used in web scrapping for turning JavaScript objects embedded in pages into valid Python dictionaries.
In web scraping this is particularly useful for parsing Javascript variables like:
import chompjs
js = """
var myObj = {
myMethod: function(params) {
// ...
},
myValue: 100
}
"""
chompjs.parse_js_object(js, json_params={'strict': False})
{'myMethod': 'function(params) {\n // ...\n }', 'myValue': 100}
In practice this can be used to extract hidden JSON data like data from <script id=__NEXT_DATA__> elements
from nextjs (and similar) websites. Unlike json.loads command chompjs can ingest json documents that contain
javascript natives like functions making it a super easy way to scrape hidden web data objects.
Example Use
const cheerio = require('cheerio');
const $ = cheerio.load('<html><head><title>My title</title></head><body><h1 class='name'>Hello World!</h1></body></html>');
// use css selectors
console.log($('title').text()); // My title
console.log($('.name').text()); // Hello World!
// select multiple elements
const $ = cheerio.load('<html><body><ul><li>item 1</li><li>item 2</li></ul></body></html>');
$('li').each(function(i, elem) {
console.log($(this).text());
});
// modify elements
const $ = cheerio.load('<html><body><h1>Hello World!</h1></body></html>');
$('h1').text('Hello, Cheerio!');
console.log($.html());
# basic use
import chompjs
js = """
var myObj = {
myMethod: function(params) {
// ...
},
myValue: 100
}
"""
chompjs.parse_js_object(js, json_params={'strict': False})
{'myMethod': 'function(params) {\n // ...\n }', 'myValue': 100}
# example how to use with hidden data parsing:
import httpx
import chompjs
from parsel import Selector
response = httpx.get("http://example.com")
hidden_script = Selector(response.text).css("script#__NEXT_DATA__::text").get()
data = chompjs.parse_js_object(hidden_script)
print(data['props'])