Small diff cleanups

Author: jbrockmendel

pandas/core/arrays/timedeltas.py

@@ -259,8 +259,8 @@ def _generate_range(cls, start, end, periods, freq, closed=None):
     # DatetimeLike Interface
 
     def _unbox_scalar(self, value):
-        if not isinstance(value, (self._scalar_type, type(NaT))):
-            raise ValueError("'value' should be a a Timestamp.")
+        if not isinstance(value, self._scalar_type) and value is not NaT:
+            raise ValueError("'value' should be a Timedelta.")
         self._check_compatible_with(value)
         return value.value
 

pandas/core/indexes/timedeltas.py

@@ -345,8 +345,8 @@ def astype(self, dtype, copy=True):
         dtype = pandas_dtype(dtype)
         if is_timedelta64_dtype(dtype) and not is_timedelta64_ns_dtype(dtype):
             # Have to repeat the check for 'timedelta64' (not ns) dtype
-            # so that we can return a numeric index, since pandas will return
-            # a TimedeltaIndex when dtype='timedelta'
+            #  so that we can return a numeric index, since pandas will return
+            #  a TimedeltaIndex when dtype='timedelta'
             result = self._data.astype(dtype, copy=copy)
             if self.hasnans:
                 return Index(result, name=self.name)

pandas/tests/arithmetic/test_datetime64.py

@@ -1981,7 +1981,7 @@ def test_dti_sub_tdi(self, tz_naive_fixture):
         result = dti - tdi
         tm.assert_index_equal(result, expected)
 
-        msg = 'cannot subtract .*TimedeltaArray'
+        msg = 'cannot subtract .*TimedeltaArrayMixin'
         with pytest.raises(TypeError, match=msg):
             tdi - dti
 

pandas/tests/indexes/datetimes/test_astype.py

@@ -177,7 +177,7 @@ def test_astype_object_with_nat(self):
     def test_astype_raises(self, dtype):
         # GH 13149, GH 13209
         idx = DatetimeIndex(['2016-05-16', 'NaT', NaT, np.NaN])
-        msg = 'Cannot cast DatetimeArray(Mixin)? to dtype'
+        msg = 'Cannot cast DatetimeArrayMixin to dtype'
         with pytest.raises(TypeError, match=msg):
             idx.astype(dtype)
 

pandas/tests/indexes/timedeltas/test_astype.py

@@ -84,7 +84,7 @@ def test_astype_timedelta64(self):
     def test_astype_raises(self, dtype):
         # GH 13149, GH 13209
         idx = TimedeltaIndex([1e14, 'NaT', NaT, np.NaN])
-        msg = 'Cannot cast TimedeltaArray(Mixin)? to dtype'
+        msg = 'Cannot cast TimedeltaArrayMixin to dtype'
         with pytest.raises(TypeError, match=msg):
             idx.astype(dtype)