Skip to content

BUG: df.reset_index loses tz #7533

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 21, 2014
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion doc/source/v0.14.1.txt
Original file line number Diff line number Diff line change
Expand Up @@ -252,7 +252,7 @@ Bug Fixes

- Bug in ``Index.astype(float)`` where it would return an ``object`` dtype
``Index`` (:issue:`7464`).

- Bug in ``DataFrame.reset_index`` loses ``tz`` (:issue:`3950`)


- Bug in non-monotonic ``Index.union`` may preserve ``name`` incorrectly (:issue:`7458`)
Expand Down
41 changes: 20 additions & 21 deletions pandas/core/frame.py
Original file line number Diff line number Diff line change
Expand Up @@ -2326,19 +2326,24 @@ def reset_index(self, level=None, drop=False, inplace=False, col_level=0,
else:
new_obj = self.copy()

def _maybe_cast(values, labels=None):

if values.dtype == np.object_:
values = lib.maybe_convert_objects(values)

# if we have the labels, extract the values with a mask
if labels is not None:
mask = labels == -1
values = values.take(labels)
if mask.any():
values, changed = com._maybe_upcast_putmask(
values, mask, np.nan)

def _maybe_casted_values(index, labels=None):
if isinstance(index, PeriodIndex):
values = index.asobject
elif (isinstance(index, DatetimeIndex) and
index.tz is not None):
values = index.asobject
else:
values = index.values
if values.dtype == np.object_:
values = lib.maybe_convert_objects(values)

# if we have the labels, extract the values with a mask
if labels is not None:
mask = labels == -1
values = values.take(labels)
if mask.any():
values, changed = com._maybe_upcast_putmask(values,
mask, np.nan)
return values

new_index = np.arange(len(new_obj))
Expand Down Expand Up @@ -2371,7 +2376,7 @@ def _maybe_cast(values, labels=None):
col_name = tuple(name_lst)

# to ndarray and maybe infer different dtype
level_values = _maybe_cast(lev.values, lab)
level_values = _maybe_casted_values(lev, lab)
if level is None or i in level:
new_obj.insert(0, col_name, level_values)

Expand All @@ -2387,13 +2392,7 @@ def _maybe_cast(values, labels=None):
lev_num = self.columns._get_level_number(col_level)
name_lst[lev_num] = name
name = tuple(name_lst)
if isinstance(self.index, PeriodIndex):
values = self.index.asobject
elif (isinstance(self.index, DatetimeIndex) and
self.index.tz is not None):
values = self.index.asobject
else:
values = _maybe_cast(self.index.values)
values = _maybe_casted_values(self.index)
new_obj.insert(0, name, values)

new_obj.index = new_index
Expand Down
14 changes: 14 additions & 0 deletions pandas/tests/test_frame.py
Original file line number Diff line number Diff line change
Expand Up @@ -2182,6 +2182,20 @@ def test_set_index_cast_datetimeindex(self):
df.pop('ts')
assert_frame_equal(df, expected)

# GH 3950
# reset_index with single level
for tz in ['UTC', 'Asia/Tokyo', 'US/Eastern']:
idx = pd.date_range('1/1/2011', periods=5, freq='D', tz=tz, name='idx')
df = pd.DataFrame({'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']}, index=idx)

expected = pd.DataFrame({'idx': [datetime(2011, 1, 1), datetime(2011, 1, 2),
datetime(2011, 1, 3), datetime(2011, 1, 4),
datetime(2011, 1, 5)],
'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']},
columns=['idx', 'a', 'b'])
expected['idx'] = expected['idx'].apply(lambda d: pd.Timestamp(d, tz=tz))
assert_frame_equal(df.reset_index(), expected)

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)
Expand Down
40 changes: 40 additions & 0 deletions pandas/tests/test_multilevel.py
Original file line number Diff line number Diff line change
Expand Up @@ -2078,6 +2078,46 @@ def test_set_index_datetime(self):
self.assertTrue(df.index.get_level_values(1).equals(idx2))
self.assertTrue(df.index.get_level_values(2).equals(idx3))

def test_reset_index_datetime(self):
# GH 3950
for tz in ['UTC', 'Asia/Tokyo', 'US/Eastern']:
idx1 = pd.date_range('1/1/2011', periods=5, freq='D', tz=tz, name='idx1')
idx2 = pd.Index(range(5), name='idx2')
idx = pd.MultiIndex.from_arrays([idx1, idx2])
df = pd.DataFrame({'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']}, index=idx)

expected = pd.DataFrame({'idx1': [datetime.datetime(2011, 1, 1),
datetime.datetime(2011, 1, 2),
datetime.datetime(2011, 1, 3),
datetime.datetime(2011, 1, 4),
datetime.datetime(2011, 1, 5)],
'idx2': range(5),
'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']},
columns=['idx1', 'idx2', 'a', 'b'])
expected['idx1'] = expected['idx1'].apply(lambda d: pd.Timestamp(d, tz=tz))
assert_frame_equal(df.reset_index(), expected)

idx3 = pd.date_range('1/1/2012', periods=5, freq='MS', tz='Europe/Paris', name='idx3')
idx = pd.MultiIndex.from_arrays([idx1, idx2, idx3])
df = pd.DataFrame({'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']}, index=idx)

expected = pd.DataFrame({'idx1': [datetime.datetime(2011, 1, 1),
datetime.datetime(2011, 1, 2),
datetime.datetime(2011, 1, 3),
datetime.datetime(2011, 1, 4),
datetime.datetime(2011, 1, 5)],
'idx2': range(5),
'idx3': [datetime.datetime(2012, 1, 1),
datetime.datetime(2012, 2, 1),
datetime.datetime(2012, 3, 1),
datetime.datetime(2012, 4, 1),
datetime.datetime(2012, 5, 1)],
'a': range(5), 'b': ['A', 'B', 'C', 'D', 'E']},
columns=['idx1', 'idx2', 'idx3', 'a', 'b'])
expected['idx1'] = expected['idx1'].apply(lambda d: pd.Timestamp(d, tz=tz))
expected['idx3'] = expected['idx3'].apply(lambda d: pd.Timestamp(d, tz='Europe/Paris'))
assert_frame_equal(df.reset_index(), expected)

def test_set_index_period(self):
# GH 6631
df = DataFrame(np.random.random(6))
Expand Down