database.py 文件源码

def create_from_settings(cls, instance, conf):
        try:
            engine_path, _, cls_name = conf['ENGINE'].rpartition('.')
            db_name = conf['NAME']
            db_options = conf['OPTIONS'] if 'OPTIONS' in conf and conf['OPTIONS'] else dict()

            # FIX for #331. Replace utf8 by utf8mb4 in the mysql driver encoding.
            if conf['ENGINE'] == 'peewee_async.MySQLDatabase' and 'charset' in db_options and db_options['charset'] == 'utf8':
                logging.info('Forcing to use \'utf8mb4\' instead of \'utf8\' for the MySQL charset option! (Fix #331).')
                db_options['charset'] = 'utf8mb4'

            # We will try to load it so we have the validation inside this class.
            engine = getattr(importlib.import_module(engine_path), cls_name)
        except ImportError:
            raise ImproperlyConfigured('Database engine doesn\'t exist!')
        except Exception as e:
            raise ImproperlyConfigured('Database configuration isn\'t complete or engine could\'t be found!')

        return cls(engine, instance, db_name, **db_options)