Small fixes

Author: ryankarlos

pandas/core/tools/timedeltas.py

@@ -2,8 +2,9 @@
 timedelta support tools
 """
 
-import numpy as np
 import warnings
+import numpy as np
+
 
 from pandas._libs import tslibs
 from pandas._libs.tslibs.timedeltas import (
@@ -93,7 +94,7 @@ def to_timedelta(arg, unit='ns', box=True, errors='raise'):
         raise ValueError("errors must be one of 'ignore', "
                          "'raise', or 'coerce'}")
 
-    if unit in ['Y', 'y', 'M']:
+    if unit in {'Y', 'y', 'M'}:
         warnings.warn("M and Y units are deprecated.",
                       FutureWarning, stacklevel=2)
 

pandas/tests/scalar/timedelta/test_timedelta.py

@@ -356,11 +356,10 @@ def test_unit_parser(self, units, np_unit, wrapper):
 
     @pytest.mark.parametrize('units', ['Y', 'y', 'M'])
     def test_unit_M_Y_deprecated(self, units):
-        for unit in units:
-            with tm.assert_produces_warning(FutureWarning):
-                to_timedelta(10, unit)
-                TimedeltaIndex([1, 1, 1], unit)
-                Timedelta(10, unit)
+        with tm.assert_produces_warning(FutureWarning):
+            to_timedelta(10, units)
+            TimedeltaIndex([1, 1, 1], units)
+            Timedelta(10, units)
 
     def test_numeric_conversions(self):
         assert ct(0) == np.timedelta64(0, 'ns')