问在django中验证错误时将css类添加到字段

EN

class MyForm(ModelForm):
    error_css_class = 'error'

def submit_form(request):
    if request.method = 'POST':
        if. form.is_valid():
            # Do something with clean form data
            pass
        else:
            # Append css class to every field that contains errors.
            for field in form.errors:
                form[field].field.widget.attrs['class'] += ' my-css-class'
    return render(request, submit_form.html, {
        'form': form
    })

.error input, .error select {
    border: 2px red solid;
}