flask的flask_restful添加二级路由

from flask import Flask
from flask_restful import Api, Resource

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

class ParentResource(Resource):
    def get(self):
        return {'message': 'This is the parent resource'}

    class ChildResource(Resource):
        def get(self):
            return {'message': 'This is the child resource'}

api.add_resource(ParentResource, '/api/Parent')
api.add_resource(ParentResource.ChildResource, '/api/Parent/Child')

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