lxmlvsxmltodict
lxml is a low-level XML and HTML tree processor. It's used by many other libraries such as parsel or beautifulsoup for higher level HTML parsing.
One of the main features of lxml is its speed and efficiency.
It is built on top of the libxml2 and libxslt C libraries, which are known for their high performance and low memory footprint.
This makes lxml well-suited for processing large and complex XML and HTML documents.
One of the key components of lxml is the ElementTree API, which is modeled after the ElementTree API from the Python standard library's xml module. This API provides a simple and intuitive way to access and manipulate the elements and attributes of an XML or HTML document. It also provides a powerful and flexible Xpath engine that allows you to select elements based on their names, attributes, and contents.
Another feature of lxml is its support for parsing and creating XML documents using the XSLT standard. The lxml library provides a powerful and easy-to-use interface for applying XSLT stylesheets to XML documents, which can be used to transform and convert XML documents into other formats, such as HTML, PDF, or even other XML formats.
For web scraping it's best to use other higher level libraries that use lxml like parsel or beautifulsoup
xmltodict is a Python library that allows you to work with XML data as if it were JSON. It allows you to parse XML documents and convert them to dictionaries, which can then be easily manipulated using standard dictionary operations.
You can also use the library to convert a dictionary back into an XML document. xmltodict is built on top of the popular lxml library and provides a simple, intuitive API for working with XML data.
Note that despite using lxml conversion speeds can be quite slow for large XML documents and in web scraping this should be used to parse specific snippets instead of whole HTML documents.
xmltodict pairs well with JSON parsing tools like jmespath or jsonpath. Alternatively, it can be used in reverse mode to parse JSON documents using HTML parsing tools like CSS selectors and XPath.
It can be installed via pip by running pip install xmltodict command.
Highlights
Example Use
from lxml import etree
# 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>
"""
tree = tree.fromstring(html)
# for parsing, LXML only supports XPath selectors:
tree.xpath('//span[@class="price"]')[0].text
"$10"
import xmltodict
xml_string = """
<book>
<title>The Great Gatsby</title>
<author>F. Scott Fitzgerald</author>
<publisher>Charles Scribner's Sons</publisher>
<publication_date>1925</publication_date>
</book>
"""
book_dict = xmltodict.parse(xml_string)
print(book_dict)
{'book': {'title': 'The Great Gatsby',
'author': 'F. Scott Fitzgerald',
'publisher': "Charles Scribner's Sons",
'publication_date': '1925'}}
# and to reverse:
book_xml = xmltodict.unparse(book_dict)
print(book_xml)
# the xml can be loaded and parsed using parsel or beautifulsoup:
from parsel import Selector
sel = Selector(book_xml)
print(sel.css('publication_date::text').get())
'1925'