astype changes

Author: TomAugspurger

pandas/core/indexes/base.py

@@ -22,7 +22,8 @@
     is_dtype_union_equal, is_extension_array_dtype, is_float, is_float_dtype,
     is_hashable, is_integer, is_integer_dtype, is_interval_dtype, is_iterator,
     is_list_like, is_object_dtype, is_period_dtype, is_scalar,
-    is_signed_integer_dtype, is_timedelta64_dtype, is_unsigned_integer_dtype)
+    is_signed_integer_dtype, is_timedelta64_dtype, is_unsigned_integer_dtype,
+    pandas_dtype)
 import pandas.core.dtypes.concat as _concat
 from pandas.core.dtypes.generic import (
     ABCDataFrame, ABCDateOffset, ABCDatetimeArray, ABCIndexClass,
@@ -732,6 +733,12 @@ def astype(self, dtype, copy=True):
             from .category import CategoricalIndex
             return CategoricalIndex(self.values, name=self.name, dtype=dtype,
                                     copy=copy)
+        elif is_datetime64tz_dtype(dtype):
+            # avoid FutureWarning from DatetimeIndex constructor.
+            from pandas import DatetimeIndex
+            tz = pandas_dtype(dtype).tz
+            return (DatetimeIndex(np.asarray(self))
+                    .tz_localize("UTC").tz_convert(tz))
 
         elif is_extension_array_dtype(dtype):
             return Index(np.asarray(self), dtype=dtype, copy=copy)

pandas/tests/indexes/datetimes/test_astype.py

@@ -238,21 +238,10 @@ def _check_rng(rng):
         ['US/Pacific', 'datetime64[ns, US/Pacific]'],
         [None, 'datetime64[ns]']])
     def test_integer_index_astype_datetime(self, tz, dtype):
-        # GH 20997, 20964
+        # GH 20997, 20964, 24559
         val = [pd.Timestamp('2018-01-01', tz=tz).value]
-
-        if tz:
-            ex_warn = FutureWarning
-        else:
-            ex_warn = None
-
-        with tm.assert_produces_warning(ex_warn):
-            # XXX: This likely shouldn't warn.
-            # This raised on 0.24.x, so we can probably do the right thing
-            # now.
-            result = pd.Index(val).astype(dtype)
-        with tm.assert_produces_warning(ex_warn):
-            expected = pd.DatetimeIndex(val, tz=tz)
+        result = pd.Index(val).astype(dtype)
+        expected = pd.DatetimeIndex(["2018-01-01"], tz=tz)
         tm.assert_index_equal(result, expected)