Django template filter to add attributes to form fields

gistfile1.py

# From http://vanderwijk.info/blog/adding-css-classes-formfields-in-django-templates/#comment-1193609278

from django import template
register = template.Library()

@register.filter(name='add_attributes')
def add_attributes(field, css):
    attrs = {}
    definition = css.split(',')

    for d in definition:
        if ':' not in d:
            attrs['class'] = d
        else:
            t, v = d.split(':')
            attrs[t] = v

    return field.as_widget(attrs=attrs)

This is great! Any interest in making it a standalone package?

can not add class to 'widget=forms.RadioSelect'
input is ok
why? can you fix it ?

for example，you want to add "style:width:20px",
there will be a collision between the Colon in the template and the colon in the python code.
so,you can change the : to = in the register.

There is also a problem if you want to add multiple classes (like form-control selectpicker) (https://silviomoreto.github.io/bootstrap-select/examples/#styling).

What I've done is use collections.defaultdict(str) instead of a simple dict, then just add to the css attribute.

def addcss(field, css):
    try:
        attrs = collections.defaultdict(str)
        definition = css.split(',')
        for d in definition:
            if ':' not in d:
                attrs['class'] += " %s"%d
            else:
                t, v = d.split(':')
                attrs[t] = v
        return field.as_widget(attrs=attrs)
    except Exception as e:
        return field