def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def _drop_schema(self, force_drop=False):
        """ Drops the schema"""
        connection = connections[get_tenant_database_alias()]
        has_schema = hasattr(connection, 'schema_name')
        if has_schema and connection.schema_name not in (self.schema_name, get_public_schema_name()):
            raise Exception("Can't delete tenant outside it's own schema or "
                            "the public schema. Current schema is %s."
                            % connection.schema_name)

        if has_schema and schema_exists(self.schema_name) and (self.auto_drop_schema or force_drop):
            self.pre_drop()
            cursor = connection.cursor()
            cursor.execute('DROP SCHEMA "%s" CASCADE' % self.schema_name)