Yes, you can parse HTML fragments that are not well-formed using the lxml library. lxml provides powerful support for parsing both well-formed and malformed HTML documents. It achieves this through its lxml.html module, which is specifically designed for handling HTML as opposed to XML, which requires well-formed content.
The lxml.html module utilizes the HTML parser from the libxml2 library, which is lenient and designed to handle the kinds of messy HTML commonly found in the wild on the web. This means that even if your HTML is not well-formed, lxml.html can usually parse it effectively.
Here's an example of how you can parse a non-well-formed HTML fragment using lxml in Python:
from lxml import html
# This is a string containing a non-well-formed HTML fragment
html_fragment = """
<html>
<body>
<p>Paragraph 1<p>Paragraph 2
<div>Unclosed div
</body>
</html>
"""
# Parse the HTML fragment
doc = html.fragment_fromstring(html_fragment, create_parent='body')
# Pretty print the parsed HTML
print(html.tostring(doc, pretty_print=True).decode('utf-8'))
In the example above, the fragment_fromstring function is used to parse a fragment of HTML. Notice that the HTML lacks closing p tags and has an unclosed div tag. The create_parent argument can be used to specify a parent element that should wrap the fragment if it consists of multiple elements at the top level.
If you have a complete HTML document that is not well-formed, you can use the html.document_fromstring or html.parse functions:
# Parse a complete HTML document
doc = html.document_fromstring(html_fragment)
# Or parse the HTML from a file or file-like object
# doc = html.parse('path_to_html_file.html')
Both document_fromstring and parse will handle non-well-formed HTML and can be used to parse an entire document, including the DOCTYPE, if present.
Keep in mind that while lxml can handle non-well-formed HTML, there may be cases where the HTML is so malformed that even a lenient parser like lxml.html may not be able to parse it correctly. In such cases, you might need to perform some pre-processing on the HTML to correct the most egregious errors before parsing.
