def update_widget_attrs(self, bound_field, attrs):
        """
        Update the dictionary of attributes used  while rendering the input widget
        """
        bound_field.form.update_widget_attrs(bound_field, attrs)
        widget_classes = self.widget.attrs.get('class', None)
        if widget_classes:
            if 'class' in attrs:
                attrs['class'] += ' ' + widget_classes
            else:
                attrs.update({'class': widget_classes})
        return attrs
def update_widget_attrs ( self , bound_field , attrs ) : bound_field . form . update_widget_attrs ( bound_field , attrs ) widget_classes = self . widget . attrs . get ( 'class' , None ) if widget_classes : if 'class' in attrs : attrs [ 'class' ] += ' ' + widget_classes else : attrs . update ( { 'class' : widget_classes } ) return attrs
Update the dictionary of attributes used  while rendering the input widget