Added support for negative indexes to PurePath.parents (GH-21799)
This commit also fixes up some of the overlapping documentation changed
in bpo-35498, which added support for indexing with slices.
Fixes bpo-21041.
https://bugs.python.org/issue21041
Co-authored-by: Paul Ganssle <p.ganssle@gmail.com>
Co-authored-by: Rémi Lapeyre <remi.lapeyre@henki.fr>
diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index 2071e7e..2bbf3aa 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -337,7 +337,7 @@
PureWindowsPath('c:/')
.. versionchanged:: 3.10
- Slice support was added.
+ The parents sequence now supports :term:`slices <slice>` and negative index values.
.. data:: PurePath.parent
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst
index ce66b1d..f3e433a 100644
--- a/Doc/whatsnew/3.10.rst
+++ b/Doc/whatsnew/3.10.rst
@@ -247,9 +247,13 @@
pathlib
-------
-Added slice support to :meth:`~pathlib.Path.parents`.
+Added slice support to :attr:`PurePath.parents <pathlib.PurePath.parents>`.
(Contributed by Joshua Cannon in :issue:`35498`)
+Added negative indexing support to :attr:`PurePath.parents
+<pathlib.PurePath.parents>`.
+(Contributed by Yaroslav Pankovych in :issue:`21041`)
+
py_compile
----------
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index af31039..531a699 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -632,7 +632,8 @@
def __getitem__(self, idx):
if isinstance(idx, slice):
return tuple(self[i] for i in range(*idx.indices(len(self))))
- if idx < 0 or idx >= len(self):
+
+ if idx >= len(self) or idx < -len(self):
raise IndexError(idx)
return self._pathcls._from_parsed_parts(self._drv, self._root,
self._parts[:-idx - 1])
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index f145179..5e5e065 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -440,6 +440,9 @@
self.assertEqual(par[0], P('a/b'))
self.assertEqual(par[1], P('a'))
self.assertEqual(par[2], P('.'))
+ self.assertEqual(par[-1], P('.'))
+ self.assertEqual(par[-2], P('a'))
+ self.assertEqual(par[-3], P('a/b'))
self.assertEqual(par[0:1], (P('a/b'),))
self.assertEqual(par[:2], (P('a/b'), P('a')))
self.assertEqual(par[:-1], (P('a/b'), P('a')))
@@ -448,7 +451,7 @@
self.assertEqual(par[::-1], (P('.'), P('a'), P('a/b')))
self.assertEqual(list(par), [P('a/b'), P('a'), P('.')])
with self.assertRaises(IndexError):
- par[-1]
+ par[-4]
with self.assertRaises(IndexError):
par[3]
with self.assertRaises(TypeError):
diff --git a/Misc/ACKS b/Misc/ACKS
index 16bc42f..2533490 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1283,6 +1283,7 @@
Richard Oudkerk
Russel Owen
Joonas Paalasmaa
+Yaroslav Pankovych
Martin Packman
Elisha Paine
Shriphani Palakodety
diff --git a/Misc/NEWS.d/next/Library/2018-12-14-13-29-17.bpo-35498.LEJHl7.rst b/Misc/NEWS.d/next/Library/2018-12-14-13-29-17.bpo-35498.LEJHl7.rst
index fb24ce0..1ab0093 100644
--- a/Misc/NEWS.d/next/Library/2018-12-14-13-29-17.bpo-35498.LEJHl7.rst
+++ b/Misc/NEWS.d/next/Library/2018-12-14-13-29-17.bpo-35498.LEJHl7.rst
@@ -1 +1 @@
-Add slice support to :meth:`~pathlib.Path.parents`.
+Add slice support to :attr:`pathlib.PurePath.parents`.
diff --git a/Misc/NEWS.d/next/Library/2020-08-10-15-06-55.bpo-21041.cYz1eL.rst b/Misc/NEWS.d/next/Library/2020-08-10-15-06-55.bpo-21041.cYz1eL.rst
new file mode 100644
index 0000000..4f14fd3
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-08-10-15-06-55.bpo-21041.cYz1eL.rst
@@ -0,0 +1 @@
+:attr:`pathlib.PurePath.parents` now supports negative indexing. Patch contributed by Yaroslav Pankovych.