diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index ce1e6128d..71c424244 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -135,7 +135,7 @@ ACTION_MAP = {
 
 def parse_key_name(pth):
     # strip the first '/' left by urlparse
-    return pth[1:] if pth.startswith('/') else pth
+    return pth[1:] if pth.startswith("/") else pth
 
 
 def is_delete_keys(request, path, bucket_name):
diff --git a/tests/test_s3/test_s3.py b/tests/test_s3/test_s3.py
index 3048f6507..fea76b9e3 100644
--- a/tests/test_s3/test_s3.py
+++ b/tests/test_s3/test_s3.py
@@ -3744,18 +3744,18 @@ def test_root_dir_with_empty_name_works():
     store_and_read_back_a_key("/")
 
 
-@parameterized(['mybucket', 'my.bucket'])
+@parameterized(["mybucket", "my.bucket"])
 @mock_s3
 def test_leading_slashes_not_removed(bucket_name):
     """Make sure that leading slashes are not removed internally."""
     s3 = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
     s3.create_bucket(Bucket=bucket_name)
 
-    uploaded_key = '/key'
-    invalid_key_1 = 'key'
-    invalid_key_2 = '//key'
+    uploaded_key = "/key"
+    invalid_key_1 = "key"
+    invalid_key_2 = "//key"
 
-    s3.put_object(Bucket=bucket_name, Key=uploaded_key, Body=b'Some body')
+    s3.put_object(Bucket=bucket_name, Key=uploaded_key, Body=b"Some body")
 
     with assert_raises(ClientError) as e:
         s3.get_object(Bucket=bucket_name, Key=invalid_key_1)