def bump_prefix(self, exceptions=()):
        """
        Changes the alias prefix to the next letter in the alphabet and
        relabels all the aliases. Even tables that previously had no alias will
        get an alias after this call (it's mostly used for nested queries and
        the outer query will already be using the non-aliased table name).

        Subclasses who create their own prefix should override this method to
        produce a similar result (a new prefix and relabelled aliases).

        The 'exceptions' parameter is a container that holds alias names which
        should not be changed.
        """
        current = ord(self.alias_prefix)
        assert current < ord('Z')
        prefix = chr(current + 1)
        self.alias_prefix = prefix
        change_map = SortedDict()
        for pos, alias in enumerate(self.tables):
            if exceptions in alias:
                continue
            new_alias = '%s%d' % (prefix, pos)
            change_map[alias] = new_alias
            self.tables[pos] = new_alias
        self.change_aliases(change_map)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/models/sql/query.py/Query.bump_prefix/swapped operands of `in`