python flask-restful无法在资源类中获取应用程序访问权限

Question

以下是来自flask-restful doc的示例代码

from flask import Flask
from flask.ext import restful

app = Flask(__name__)
api = restful.Api(app)

class HelloWorld(restful.Resource):
    def get(self):
        return {'hello': 'world'}

api.add_resource(HelloWorld, '/')

if __name__ == '__main__':
    app.run(debug=True)

这个HelloWorld类在同一个python文件中,比方说app.py,它有效.

现在我将把HelloWorld类放到一个单独的类文件中,如下面的布局:

app
app/__init__.py # hold above code except the HelloWorld class.
app/resource
app/resource/__init__.py # empty
app/resource/HelloWorld.py # hold the above HelloWorld class.

该app/__init__.py包含:

from flask import Flask
from flask.ext import restful
from resource.HelloWorld import HelloWorld

app = Flask(__name__)
api = restful.Api(app)

api.add_resource(HelloWorld, '/')

if __name__ == '__main__':
    app.run(debug=True)

而且HelloWorld.py是:

from flask.ext import restful
from app import app

class HelloWorld(restful.Resource):
    def get(self):
        return {'hello': 'world'}

运行应用程序会出现异常:

ImportError: No module named app on HelloWorld.py

我确实需要访问应用程序来阅读一些信息,例如app.config,我如何使其工作？

Answer 1

你有一个循环导入; 当行from resource.HelloWorld import HelloWorld执行时,app尚未分配给,所以Helloworld.py在行中from app import app失败.

要么HelloWorld稍后导入:

from flask import Flask
from flask.ext import restful

app = Flask(__name__)
api = restful.Api(app)

from resource.HelloWorld import HelloWorld
api.add_resource(HelloWorld, '/')

if __name__ == '__main__':
    app.run(debug=True)

或者只导入app模块HelloWorld.py:

from flask.ext import restful
import app

class HelloWorld(restful.Resource):
    def get(self):
        return {'hello': 'world'}

并app.app在稍后调用的函数或方法中引用.