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I am having a dilemma where two modules import each other.

In this Flask-restplus application, app.py is the entry point which Flask app and SQLAlchemy db instance are initialized.

import settings
from apis.rest import api
from apis.audio_namespace import ns as audio_namespace

log = logging.getLogger(__name__)
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = settings.DATABASE

db = SQLAlchemy(app)

def configure_app(flask_app):
    flask_app.config['SERVER_NAME'] = settings.FLASK_SERVER_NAME

def initialize_app(flask_app):
    configure_app(flask_app)
    blueprint = Blueprint('api', __name__, url_prefix='/api')
    api.init_app(blueprint)
    api.add_namespace(audio_namespace)
    flask_app.register_blueprint(blueprint)

def main():
    initialize_app(app)
    app.run(debug=settings.FLASK_DEBUG)

if __name__ == "__main__":
    main()

The namespace audio_namespace from folder apis is added to api. api is defined in rest from folder apis too.

#rest.py
api = Api(version='1.0', title='SoundAPI',
          description='API for audio processing with TensorFlow')

audio_namespace.py handles all the requests and hence db operations. 

ns = api.namespace('audio', description='Audio processing with TensorFlow')
class AudioDAO(object):
    @property
    def audios(self):
        return AudioModel.query.all()

    def get(self, id):
        audio = AudioModel.query.filter_by(id=id).first()
        if audio:
            return {"id": audio.id, "filename": audio.file_name}
        api.abort(404, "Audio {} doesn't exist".format(id))

    def create(self, file_name):
        audio = AudioModel(file_name)
        audio.insert_ts = datetime.now()
        db.session.add(audio)
        db.session.commit()
        return audio
@ns.route('/upload')
class AudioUpload(Resource):
    def put(self):
 ...........

    def post(self):
...........

But since db is defined in app.py, I would have to import db from app. Therefore I got error saying ns from audio_namespace can't be imported in app.py because the two modules cannot import each other.

Where should I define db then?

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1 回答 1

2

I don't know if this will help you, but you could try to instance SqlAlchemy without app and then create your app and call db.init_app(app) in initialize_app and return your app in that method.

Right now I'm on mobile so I can't write code, I'll link an example here:

Link

于 2018-05-02T10:50:25.230 回答