### Defining Example HTML and Fragment Strings
Source: https://github.com/rushter/selectolax/blob/master/examples/walkthrough.ipynb
Initializes multi-line string variables `html` and `fragment` containing example HTML structures. These strings are used throughout the tutorial for parsing and manipulation demonstrations.
```python
html = """
Excepteur sint occaecat cupidatat non proident
Lorem ipsum
Lorem Ipsum is simply dummy text of the printing and typesetting industry.
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
"""
tree = HTMLParser(html)
# tree.css_first('h1#title').text()
# Out[2]: 'Hi there'
# tree.css_first('h1#title').attributes
# Out[3]: {'id': 'title', 'data-updated': '20201101'}
# [node.text() for node in tree.css('.post')]
# Out[4]:
# ['Lorem Ipsum is simply dummy text of the printing and typesetting industry. ',
# 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.']
```
--------------------------------
### Use LexborHTMLParser backend in selectolax
Source: https://github.com/rushter/selectolax/blob/master/README.rst
Demonstrates how to explicitly use the `LexborHTMLParser` backend, which is the preferred and actively maintained option in selectolax. It shows parsing HTML and extracting text from an element using CSS selectors, similar to the default `HTMLParser`.
```python
from selectolax.lexbor import LexborHTMLParser
html = """