__init__.py 文件源码

def get_app(self, reference_app=None):
        """Helper method that implements the logic to look up an
        application."""

        if reference_app is not None:
            return reference_app

        if current_app:
            return current_app

        if self.app is not None:
            return self.app

        raise RuntimeError(
            'application not registered on db instance and no application'
            'bound to current context'
        )