diff --git a/moto/core/models.py b/moto/core/models.py
index 491e9f451..19267ca08 100644
--- a/moto/core/models.py
+++ b/moto/core/models.py
@@ -4,7 +4,6 @@ from __future__ import absolute_import
 
 import functools
 import inspect
-import os
 import re
 import six
 from io import BytesIO
diff --git a/moto/iot/models.py b/moto/iot/models.py
index 855591ffc..5dea4ee66 100644
--- a/moto/iot/models.py
+++ b/moto/iot/models.py
@@ -944,5 +944,6 @@ class IoTBackend(BaseBackend):
 
         return job_executions, next_token
 
+
 available_regions = boto3.session.Session().get_available_regions("iot")
 iot_backends = {region: IoTBackend(region) for region in available_regions}