goqueryvsbeautifulsoup
goquery brings a syntax and a set of features similar to jQuery to the Go language. goquery is a popular and easy-to-use library for Go that allows you to use a CSS selector-like syntax to select elements from an HTML document.
It is based on Go's net/html package and the CSS Selector library cascadia. Since the net/html parser returns nodes, and not a full-featured DOM tree, jQuery's stateful manipulation functions (like height(), css(), detach()) have been left off.
Also, because the net/html parser requires UTF-8 encoding, so does goquery: it is the caller's responsibility to ensure that the source document provides UTF-8 encoded HTML. See the wiki for various options to do this. Syntax-wise, it is as close as possible to jQuery, with the same function names when possible, and that warm and fuzzy chainable interface. jQuery being the ultra-popular library that it is, I felt that writing a similar HTML-manipulating library was better to follow its API than to start anew (in the same spirit as Go's fmt package), even though some of its methods are less than intuitive (looking at you, index()...).
goquery can download HTML by itself (using built-in http client) though it's not recommended for web scraping as it's likely to be blocked.
beautifulsoup is a Python library for pulling data out of HTML and XML files. It creates parse trees from the source code that can be used to extract data from HTML, which is useful for web scraping. With beautifulsoup, you can search, navigate, and modify the parse tree. It sits atop popular Python parsers like lxml and html5lib, allowing users to try out different parsing strategies or trade speed for flexibility.
beautifulsoup has a number of useful methods and attributes that can be used to extract and manipulate data from an HTML or XML document. Some of the key features include:
- Searching the parse tree
You can search the parse tree using the various search methods that beautifulsoup provides, such as find(), find_all(), and select(). These methods take various arguments to search for specific tags, attributes, and text, and return a list of matching elements. - Navigating the parse tree
You can navigate the parse tree using the various navigation methods that beautifulsoup provides, such as next_sibling, previous_sibling, next_element, previous_element, parent, and children. These methods allow you to move up, down, and around the parse tree. - Modifying the parse tree
You can modify the parse tree using the various modification methods that beautifulsoup provides, such as append(), extend(), insert(), insert_before(), and insert_after(). These methods allow you to add new elements to the parse tree, or to change the position of existing elements. - Accessing tag attributes
You can access the attributes of a tag using the attrs property. This property returns a dictionary of the tag's attributes and their values. - Accessing tag text
You can access the text within a tag using the string property. This property returns the text as a string, with any leading or trailing whitespace removed.
With the above feature one can easily extract data out of HTML or XML files. It is widely used in web scraping and other data extraction projects.
It also has features for parsing XML files, special methods for dealing with HTML forms, pretty printing HTML and a few other functionalities.
Highlights
Example Use
package main
import (
"fmt"
"github.com/PuerkitoBio/goquery"
)
func main() {
// Use goquery.NewDocument to load an HTML document
// This can load from URL
doc, err := goquery.NewDocument("http://example.com")
// or HTML string:
doc, err := goquery.NewDocumentFromReader("some html")
if err != nil {
fmt.Println("Error:", err)
return
}
// Use the Selection.Find method to select elements from the document
doc.Find("a").Each(func(i int, s *goquery.Selection) {
// Use the Selection.Text method to get the text of the element
fmt.Println(s.Text())
// Use the Selection.Attr method to get the value of an attribute
fmt.Println(s.Attr("href"))
})
}
from bs4 import BeautifulSoup
# 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>
"""
soup = BeautifulSoup(html)
# we can iterate using dot notation:
soup.head.title
"Hello World"
# or use find method to recursively find matching elements:
soup.find(class_="price").text
"$10"
# the selected elements can be modified in place:
soup.find(class_="price").string = "$20"
# beautifulsoup also supports CSS selectors:
soup.select_one("#product .price").text
"$20"
# bs4 also contains various utility functions like HTML formatting
print(soup.prettify())
"""
<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">
$20
</span>
</div>
</body>
</html>
"""