Skip to content

BUG: RangeIndex.union #44019

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

Merged
merged 2 commits into from
Oct 16, 2021
Merged

BUG: RangeIndex.union #44019

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
58a4f33
BUG: RangeIndex.union
jbrockmendel Oct 13, 2021
78d7e2b
GH ref
jbrockmendel Oct 13, 2021
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
1 change: 1 addition & 0 deletions doc/source/whatsnew/v1.4.0.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -548,6 +548,7 @@ Styler
Other
^^^^^
- Bug in :meth:`CustomBusinessMonthBegin.__add__` (:meth:`CustomBusinessMonthEnd.__add__`) not applying the extra ``offset`` parameter when beginning (end) of the target month is already a business day (:issue:`41356`)
- Bug in :meth:`RangeIndex.union` with another ``RangeIndex`` with matching (even) ``step`` and starts differing by strictly less than ``step / 2`` (:issue:`44019`)

.. ***DO NOT USE THIS SECTION***

Expand Down
7 changes: 5 additions & 2 deletions pandas/core/indexes/range.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -635,10 +635,13 @@ def _union(self, other: Index, sort):
return type(self)(start_r, end_r + step_s, step_s)
if (
(step_s % 2 == 0)
and (abs(start_s - start_o) <= step_s / 2)
and (abs(end_s - end_o) <= step_s / 2)
and (abs(start_s - start_o) == step_s / 2)
and (abs(end_s - end_o) == step_s / 2)
):
# e.g. range(0, 10, 2) and range(1, 11, 2)
# but not range(0, 20, 4) and range(1, 21, 4) GH#44019
return type(self)(start_r, end_r + step_s / 2, step_s / 2)

elif step_o % step_s == 0:
if (
(start_o - start_s) % step_s == 0
Expand Down
9 changes: 9 additions & 0 deletions pandas/tests/indexes/ranges/test_setops.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -290,6 +290,15 @@ def test_union_sorted(self, unions):
tm.assert_index_equal(res2, expected_sorted, exact=True)
tm.assert_index_equal(res3, expected_sorted, exact="equiv")

def test_union_same_step_misaligned(self):
# GH#44019
left = RangeIndex(range(0, 20, 4))
right = RangeIndex(range(1, 21, 4))

result = left.union(right)
expected = Int64Index([0, 1, 4, 5, 8, 9, 12, 13, 16, 17])
tm.assert_index_equal(result, expected, exact=True)

def test_difference(self):
# GH#12034 Cases where we operate against another RangeIndex and may
# get back another RangeIndex
Expand Down