def post(self):
     args = userParser.parse_args()
     username = args['username']
     username = username.lower()
     user = UsersModel.fetch_by_username(username)
     if user:
         return marshal(user, userStructure), 200
     user = UsersModel(username=username)
     record = user.create_record()
     return marshal(record,userStructure),201
 def put(self,uid):
     args = userParser.parse_args()
     username = args['username'].lower()
     if UsersModel.fetch_by_username(username):
         return {"message":"Username {} already exists".format(username)},409
     updated = UsersModel.update_by_id(id=uid, newUsername=username)
     if updated:
         record = UsersModel.fetch_by_id(uid)
         return marshal(record,userStructure),200
     else:
         return {"Message":"Record not updated"},500