'Returns a SQLAlchemy criterion derived from column_filter.'

def get_filter(self, trans, user, column_filter):

    if isinstance(column_filter, string_types):
        return self.get_single_filter(user, column_filter)
    elif isinstance(column_filter, list):
        clause_list = []
        for filter in column_filter:
            clause_list.append(self.get_single_filter(user, filter))
        return and_(*clause_list)
