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Python Flask REST API API Protection User Resource

Posted by Iain Simmons
Iain Simmons
Treehouse Moderator 32,305 Points

Exception from model if username/email already exists isn't returned in JSON

Hi Kenneth Love, me again!

For the post method on the User resource, your existing code will return the built-in error page in HTML if the username or email already exists (we're raising a regular Exception on the model).

Here's a solution that will return the error message in JSON format, along with the 400 HTTP status code.

Also note that again, you don't need make_response or anything from Flask, since you can just return a dict and Flask-RESTful will properly return a JSON-encoded response from it.

users.py 
    def post(self):
        args = self.reqparse.parse_args()
        if args.get('password') == args.get('verify_password'):
            try:
                user = models.User.create_user(**args)
            except Exception as error:
                return {'error': str(error)}, 400
            else:
                return marshal(user, user_fields), 201
        return {
            'error': 'Password and password verification do not match'
        }, 400

3 Answers

Innocent Ngwaru
Innocent Ngwaru
7,554 Points
Innocent Ngwaru
Innocent Ngwaru
7,554 Points

Hi Iain. I m sorry I did not submit my question, and also asking on your question. For some reason I cannot use the 'Get Help' button. I dont know why? My question relates to Challenge 2 of 2 for Creater User in Flask Rest API, API Protection category. I have been stuck here for some time now. My code passed Challenge 1 of 2, and is as below:

@marshal_with(user_fields)
def post(self):
    args = self.reqparse.parse_args()
    if args.get('password') == args.get('confirm_password'):
        try:
            user = models.User.create_user(**args)
        except ExceptionError:
            return 'error'
        else:
            return marshal(user, user_fields), 201
    return 'Password and password verification do not match'

users_api = Blueprint('resources.users', name) api = Api(users_api) api.add_resource(UserList, '/api/v1/users')