Django MinLengthValidator that ignores HTML tags when counting characters

HTMLStrippingMinLengthValidator

from html.parser import HTMLParser

from django.core.validators import MinLengthValidator


# via http://stackoverflow.com/a/925630/2295891 (see there for Py2 version)
class MLStripper(HTMLParser):
    def __init__(self):
        super(MLStripper, self).__init__()
        self.reset()
        self.strict = False
        self.convert_charrefs = True
        self.fed = []

    def handle_data(self, d):
        self.fed.append(d)

    def get_data(self):
        return ''.join(self.fed)


def strip_tags(html):
    s = MLStripper()
    s.feed(html)
    return s.get_data()


class HTMLStrippingMinLengthValidator(MinLengthValidator):
    clean = lambda self, x: len(strip_tags(x))