Use this to get a Python dictionary of the form data given in a HTML page. lxml is used to read the form data.

form_data.py

def form_data(response: HttpResponse, **kwargs) -> dict:
    """Read form data from an HTML response."""
    return parse_html_form(response.content, **kwargs)


def parse_html_form(html: str, **kwargs) -> dict:
    """Returns form data as a dict.

    The form lookup can be narrowed down by using attributes to filter for
    as `kwargs`.
    """
    tree = lxml.html.fromstring(html)

    filter = " and ".join(f"@{key}='{val}'" for key, val in kwargs.items())
    form = tree.xpath(f"//form[{filter}]" if filter else "//form")[0]

    data = {}
    for key, element in form.inputs.items():
        match element.value:
            case lxml.html.CheckboxValues():
                data[key] = [sub.value for sub in element.value.group if sub.value]
            case lxml.html.MultipleSelectOptions():
                data[key] = list(element.value)
            case _:
                data[key] = element.value or ""
    return data