cssselectvsxmltodict
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.
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.
Example Use
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}')
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'