def __create_context(self, main_root):
		context_dir = os.path.join(main_root, 'context')
		safe_mkdir(context_dir)

		action_default = {}
		for unit, param in self.__task.data['workflow'].items():
			action_default[unit] = self.__action_mgr.default_config(param['type'])

		navigators = self.__config_mgr.navigator()
		context_format = self.__navigator_mgr.context_format(navigators)

		self.__context_mgr.create_context_file(self.__task.data, action_default, context_format, context_dir)
def _get_unique_constraints(self, table):
    """Retrieve information about existing unique constraints of the table

    This feature is needed for _recreate_table() to work properly.
    Unfortunately, it's not available in sqlalchemy 0.7.x/0.8.x.

    """

    data = table.metadata.bind.execute(
        """SELECT sql
           FROM sqlite_master
           WHERE
               type='table' AND
               name=:table_name""",
        table_name=table.name
    ).fetchone()[0]

    UNIQUE_PATTERN = "CONSTRAINT (\w+) UNIQUE \(([^\)]+)\)"
    return [
        UniqueConstraint(
            *[getattr(table.columns, c.strip(' "')) for c in cols.split(",")],
            name=name
        )
        for name, cols in re.findall(UNIQUE_PATTERN, data)
    ]