CLN: linting fixes for arithmetic tests

Author: deniederhut

pandas/tests/frame/test_arithmetic.py

@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 
-import pytest
 import numpy as np
 import pytest
 

pandas/tests/series/test_arithmetic.py

@@ -306,7 +306,7 @@ def test_ops_series_timedelta(self):
         tm.assert_series_equal(result, expected)
 
     @pytest.mark.xfail(reason="Unary negative is currently not permitted "
-                          "for objects of type TimePeriod, see GH 19297")
+                       "for objects of type TimePeriod, see GH 19297")
     def test_ops_series_period(self):
         # GH 13043
         ser = pd.Series([pd.Period('2015-01-01', freq='D'),