diff --git a/_pytest/assertion/__init__.py b/_pytest/assertion/__init__.py
index 0cdb56e07..46a5b67e6 100644
--- a/_pytest/assertion/__init__.py
+++ b/_pytest/assertion/__init__.py
@@ -2,7 +2,6 @@
 support for presenting detailed information in failing assertions.
 """
 import py
-import os
 import sys
 
 from _pytest.assertion import util
diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 24b3e719b..1c47440c3 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -579,7 +579,7 @@ class TestTruncateExplanation:
 
     # The number of lines in the truncation explanation message. Used
     # to calculate that results have the expected length.
-    LINES_IN_TRUNCATION_MSG = 2  
+    LINES_IN_TRUNCATION_MSG = 2
 
     def test_doesnt_truncate_when_input_is_empty_list(self):
         expl = []