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The experimental notebooks of Audrey M. Roy Greenfeld. This website and all its notebooks are open-source at github.com/audreyfeldroy/audrey.feldroy.com

# Accessing CSS Classes in FastHTML

by Audrey M. Roy Greenfeld | Fri, May 9, 2025

How to retrieve the CSS classes for a FastHTML FastTag instance.

from fasthtml.common import *

Here's a typical div with several Tailwind CSS classes:

d = Div(cls="container mx-auto p-4 bg-white dark:bg-gray-800")


<div class="container mx-auto p-4 bg-white dark:bg-gray-800"></div>

div((),{'class': 'container mx-auto p-4 bg-white dark:bg-gray-800'})

The FT variable d has these attrs:

d.attrs

{'class': 'container mx-auto p-4 bg-white dark:bg-gray-800'}

To get the CSS classes, you get the class attribute of d:

d.attrs['class']

'container mx-auto p-4 bg-white dark:bg-gray-800'

Then you can split the space-separated string into a list, if you like:

css_classes = d.attrs['class'].split()
css_classes

['container', 'mx-auto', 'p-4', 'bg-white', 'dark:bg-gray-800']