Not, not Non for the exception.

moto/apigateway/exceptions.py

@@ -2,11 +2,11 @@ from __future__ import unicode_literals
 from moto.core.exceptions import RESTError
 
 
-class StageNonFoundException(RESTError):
+class StageNotFoundException(RESTError):
     code = 404
     def __init__(self):
-        super(StageNonFoundException, self).__init__(
-            "NonFoundException", "Invalid stage identifier specified")
+        super(StageNotFoundException, self).__init__(
+            "NotFoundException", "Invalid stage identifier specified")
 
 
 

moto/apigateway/models.py

@@ -7,7 +7,7 @@ import requests
 from moto.core import BaseBackend
 from moto.core.utils import iso_8601_datetime_with_milliseconds
 from .utils import create_id
-from .exceptions import StageNonFoundException
+from .exceptions import StageNotFoundException
 
 STAGE_URL = "https://{api_id}.execute-api.{region_name}.amazonaws.com/{stage_name}"
 
@@ -427,7 +427,7 @@ class APIGatewayBackend(BaseBackend):
         api = self.get_rest_api(function_id)
         stage = api.stages.get(stage_name)
         if stage is None:
-            raise StageNonFoundException()
+            raise StageNotFoundException()
         else:
             return stage
 

moto/apigateway/responses.py

@@ -4,7 +4,7 @@ import json
 
 from moto.core.responses import BaseResponse
 from .models import apigateway_backends
-from .exceptions import StageNonFoundException
+from .exceptions import StageNotFoundException
 
 
 class APIGatewayResponse(BaseResponse):
@@ -136,7 +136,7 @@ class APIGatewayResponse(BaseResponse):
         if self.method == 'GET':
             try:
                 stage_response = self.backend.get_stage(function_id, stage_name)
-            except StageNonFoundException as error:
+            except StageNotFoundException as error:
                 return error.code, headers,'{{"message":"{0}","code":"{1}"}}'.format(error.message,error.error_type)
         elif self.method == 'PATCH':
             patch_operations = self._get_param('patchOperations')