Skip to content

BUG: Empty lists shouldn't be counted as DateOffsets. See #13844 #13889

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.

Sign up for GitHub

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

Closed
wants to merge 3 commits into from
Closed

BUG: Empty lists shouldn't be counted as DateOffsets. See #13844 #13889

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
179f8ce
BUG: Empty lists shouldn't be counted as DateOffsets. See #13844
tom-bird Aug 3, 2016
cb26d25
BUG: Empty lists shouldn't be counted as DateOffsets. See #13844
tom-bird Aug 7, 2016
c85b5b2
Empty lists shouldn't be counted as DateOffsets. See #13844
tom-bird Aug 21, 2016
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
5 changes: 2 additions & 3 deletions pandas/core/ops.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -597,10 +597,9 @@ def _is_offset(self, arr_or_obj):
""" check if obj or all elements of list-like is DateOffset """
if isinstance(arr_or_obj, pd.DateOffset):
return True
elif is_list_like(arr_or_obj):
elif is_list_like(arr_or_obj) and len(arr_or_obj):
return all(isinstance(x, pd.DateOffset) for x in arr_or_obj)
else:
return False
return False


def _arith_method_SERIES(op, name, str_rep, fill_zeros=None, default_axis=None,
Expand Down
8 changes: 8 additions & 0 deletions pandas/tests/series/test_timeseries.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -525,3 +525,11 @@ def test_timeseries_coercion(self):
self.assertTrue(ser.is_time_series)
self.assertTrue(ser.index.is_all_dates)
self.assertIsInstance(ser.index, DatetimeIndex)

def test_empty_series_addition(self):
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

call this test_empty_series_ops

# see issue #13844
a = Series(dtype='M8[ns]')
b = Series(dtype='m8[ns]')
assert_series_equal(a, a + b)
assert_series_equal(a, a - b)
assert_series_equal(a, b + a)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

add the b - a (which should raise)