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cssselectvshtml5-parser

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8.6 million (month) Apr 14 2012 1.2.0(2 years ago)
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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.

html5-parser is a Python library for parsing HTML and XML documents.

A fast implementation of the HTML 5 parsing spec for Python. Parsing is done in C using a variant of the gumbo parser. The gumbo parse tree is then transformed into an lxml tree, also in C, yielding parse times that can be a thirtieth of the html5lib parse times. That is a speedup of 30x. This differs, for instance, from the gumbo python bindings, where the initial parsing is done in C but the transformation into the final tree is done in python.

It is built on top of the popular lxml library and provides a simple and intuitive API for working with the document's structure.

html5-parser uses the HTML5 parsing algorithm, which is more lenient and forgiving than the traditional XML-based parsing algorithm. This means that it can parse HTML documents with malformed or missing tags and still produce a usable parse tree.

To use html5-parser, you first need to install it via pip by running pip install html5-parser. Once it is installed, you can use the html5_parser.parse() function to parse an HTML document and create a parse tree. For example:

from html5_parser import parse

html_string = "<html><body>Hello, World!</body></html>"
root = parse(html_string)
print(root.tag) # html
You can also use `html5_parser.parse()`` with file-like objects, bytes or file paths.

Once you have a parse tree, you can use the find() and findall() methods to search for elements in the document similar to BeautifulSoup.

html5-parser also supports searching using xpath, similar to lxml.

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}')
from html5_parser import parse

html_string = "<html><body>Hello, World!</body></html>"
root = parse(html_string)
print(root.tag) # html
body = root.find("body")
# or find all
print(body.text) # "Hello, World!"
for el in root.findall("p"):
    print(el.text) # "Hello

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