BUG: Bug in DataFrame.set_index() with tz-aware Series

closes #12358

Author: Jeff Reback <[email protected]>

Closes #12365 from jreback/set_index_tz and squashes the following commits:

46d5c9d [Jeff Reback] BUG: Bug in DataFrame.set_index() with tz-aware Series

Author: jreback

doc/source/whatsnew/v0.18.0.txt

@@ -1045,7 +1045,7 @@ Bug Fixes
 - Bug in ``DataFrame.info`` when duplicated column names exist (:issue:`11761`)
 - Bug in ``.copy`` of datetime tz-aware objects (:issue:`11794`)
 - Bug in ``Series.apply`` and ``Series.map`` where ``timedelta64`` was not boxed (:issue:`11349`)
-
+- Bug in ``DataFrame.set_index()`` with tz-aware ``Series`` (:issue:`12358`)
 
 
 

pandas/core/frame.py

@@ -2810,7 +2810,7 @@ def set_index(self, keys, drop=True, append=False, inplace=False,
                 level = col.get_level_values(col.nlevels - 1)
                 names.extend(col.names)
             elif isinstance(col, Series):
-                level = col.values
+                level = col._values
                 names.append(col.name)
             elif isinstance(col, Index):
                 level = col

pandas/tests/frame/test_alter_axes.py

@@ -7,7 +7,8 @@
 import numpy as np
 
 from pandas.compat import lrange
-from pandas import DataFrame, Series, Index, MultiIndex, RangeIndex
+from pandas import (DataFrame, Series, Index, MultiIndex,
+                    RangeIndex)
 import pandas as pd
 
 from pandas.util.testing import (assert_series_equal,
@@ -267,6 +268,15 @@ def test_set_index_cast_datetimeindex(self):
                 lambda d: pd.Timestamp(d, tz=tz))
             assert_frame_equal(df.reset_index(), expected)
 
+        # GH 12358
+        # tz-aware Series should retain the tz
+        i = pd.to_datetime(["2014-01-01 10:10:10"],
+                           utc=True).tz_convert('Europe/Rome')
+        df = DataFrame({'i': i})
+        self.assertEqual(df.set_index(i).index[0].hour, 11)
+        self.assertEqual(pd.DatetimeIndex(pd.Series(df.i))[0].hour, 11)
+        self.assertEqual(df.set_index(df.i).index[0].hour, 11)
+
     def test_set_index_multiindexcolumns(self):
         columns = MultiIndex.from_tuples([('foo', 1), ('foo', 2), ('bar', 1)])
         df = DataFrame(np.random.randn(3, 3), columns=columns)