Removes a filter given the attribute name

def remove_filter(self, filter_attr):
        """ Removes a filter given the attribute name """
        filter_attr = self._get_mapping(filter_attr)
        new_filters = []
        remove_chain = False

        for flt in self._filters:
            if isinstance(flt, tuple):
                if flt[0] == filter_attr:
                    remove_chain = True
                else:
                    new_filters.append(flt)
            else:
                # this is a ChainOperator
                if remove_chain is False:
                    new_filters.append(flt)
                else:
                    remove_chain = False

        self._filters = new_filters