Added slice support to PathLib parents attribute.

Author: Joshua Cannon

Lib/pathlib.py

@@ -583,6 +583,8 @@ def __len__(self):
             return len(self._parts)
 
     def __getitem__(self, idx):
+        if isinstance(idx, slice):
+            return [self[i] for i in range(*idx.indices(len(self)))]
         if idx < 0 or idx >= len(self):
             raise IndexError(idx)
         return self._pathcls._from_parsed_parts(self._drv, self._root,

Lib/test/test_pathlib.py

@@ -436,6 +436,11 @@ def test_parents_common(self):
         self.assertEqual(par[0], P('a/b'))
         self.assertEqual(par[1], P('a'))
         self.assertEqual(par[2], P('.'))
+        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')])
+        self.assertEqual(par[1:], [P('a'), P('.')])
+        self.assertEqual(par[::2], [P('a/b'), P('.')])
         self.assertEqual(list(par), [P('a/b'), P('a'), P('.')])
         with self.assertRaises(IndexError):
             par[-1]
@@ -450,6 +455,11 @@ def test_parents_common(self):
         self.assertEqual(par[0], P('/a/b'))
         self.assertEqual(par[1], P('/a'))
         self.assertEqual(par[2], P('/'))
+        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')])
+        self.assertEqual(par[1:], [P('/a'), P('/')])
+        self.assertEqual(par[::2], [P('/a/b'), P('/')])
         self.assertEqual(list(par), [P('/a/b'), P('/a'), P('/')])
         with self.assertRaises(IndexError):
             par[3]
@@ -850,6 +860,11 @@ def test_parents(self):
         self.assertEqual(len(par), 2)
         self.assertEqual(par[0], P('z:a'))
         self.assertEqual(par[1], P('z:'))
+        self.assertEqual(par[0:1], [P('z:a')])
+        self.assertEqual(par[:-1], [P('z:a')])
+        self.assertEqual(par[:2], [P('z:a'), P('z:')])
+        self.assertEqual(par[1:], [P('z:')])
+        self.assertEqual(par[::2], [P('z:a')])
         self.assertEqual(list(par), [P('z:a'), P('z:')])
         with self.assertRaises(IndexError):
             par[2]
@@ -858,6 +873,11 @@ def test_parents(self):
         self.assertEqual(len(par), 2)
         self.assertEqual(par[0], P('z:/a'))
         self.assertEqual(par[1], P('z:/'))
+        self.assertEqual(par[0:1], [P('z:/a')])
+        self.assertEqual(par[0:-1], [P('z:/a')])
+        self.assertEqual(par[:2], [P('z:/a'), P('z:/')])
+        self.assertEqual(par[1:], [P('z:/')])
+        self.assertEqual(par[::2], [P('z:/a')])
         self.assertEqual(list(par), [P('z:/a'), P('z:/')])
         with self.assertRaises(IndexError):
             par[2]
@@ -866,6 +886,11 @@ def test_parents(self):
         self.assertEqual(len(par), 2)
         self.assertEqual(par[0], P('//a/b/c'))
         self.assertEqual(par[1], P('//a/b'))
+        self.assertEqual(par[0:1], [P('//a/b/c')])
+        self.assertEqual(par[0:-1], [P('//a/b/c')])
+        self.assertEqual(par[:2], [P('//a/b/c'), P('//a/b')])
+        self.assertEqual(par[1:], [P('//a/b')])
+        self.assertEqual(par[::2], [P('//a/b/c')])
         self.assertEqual(list(par), [P('//a/b/c'), P('//a/b')])
         with self.assertRaises(IndexError):
             par[2]

Misc/ACKS

@@ -246,6 +246,7 @@ Arnaud Calmettes
 Daniel Calvelo
 Tony Campbell
 Brett Cannon
+Joshua Cannon
 Tristan Carel
 Mike Carlton
 Pierre Carrier

Misc/NEWS.d/next/Library/2018-12-14-13-29-17.bpo-35498.LEJHl7.rst

@@ -0,0 +1 @@
+Add slice support to :meth:`PathLib._PathParents.__getitem__`.