Blueprint and Flask_restful

app.py

from flask import Flask
from example_blueprint import example_blueprint

app = Flask(__name__)
app.register_blueprint(example_blueprint)
app.run(host='127.0.0.1', port=5000, debug=True)

example_blueprint.py

from flask import Blueprint
from flask_restful import Api, Resource

example_blueprint = Blueprint('example_blueprint', __name__)

rest_api_v2 = Api(example_blueprint)

class DBError(Exception):
    pass
class GremlinError(Exception):
    pass

@example_blueprint.errorhandler(GremlinError)
@example_blueprint.errorhandler(DBError)
def _errror(ex):
    return "error:" + ex.args[0]

# @example_blueprint.route('/db')
# def index():
#     raise DBError('db')
#     return "This is an example app"

# @example_blueprint.route('/gremlin')
# def gremlin():
#     raise GremlinError('gremlin')
#     return "This is an example app"

class Gremlin(Resource):
    @staticmethod
    def get():
        raise GremlinError('gremlin')

class DB(Resource):
    @staticmethod
    def get():
        raise DBError('db')


rest_api_v2.add_resource(Gremlin, "/api/gremlin")
rest_api_v2.add_resource(DB, "/api/db")