bpo-40148: Add PurePath.with_stem() (GH-19295)
Add PurePath.with_stem()
diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index d4329e7..dead49b 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -571,6 +571,30 @@
ValueError: PureWindowsPath('c:/') has an empty name
+.. method:: PurePath.with_stem(stem)
+
+ Return a new path with the :attr:`stem` changed. If the original path
+ doesn't have a name, ValueError is raised::
+
+ >>> p = PureWindowsPath('c:/Downloads/draft.txt')
+ >>> p.with_stem('final')
+ PureWindowsPath('c:/Downloads/final.txt')
+ >>> p = PureWindowsPath('c:/Downloads/pathlib.tar.gz')
+ >>> p.with_stem('lib')
+ PureWindowsPath('c:/Downloads/lib.gz')
+ >>> p = PureWindowsPath('c:/')
+ >>> p.with_stem('')
+ Traceback (most recent call last):
+ File "<stdin>", line 1, in <module>
+ File "/home/antoine/cpython/default/Lib/pathlib.py", line 861, in with_stem
+ return self.with_name(stem + self.suffix)
+ File "/home/antoine/cpython/default/Lib/pathlib.py", line 851, in with_name
+ raise ValueError("%r has an empty name" % (self,))
+ ValueError: PureWindowsPath('c:/') has an empty name
+
+ .. versionadded:: 3.9
+
+
.. method:: PurePath.with_suffix(suffix)
Return a new path with the :attr:`suffix` changed. If the original path
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 88ebe03..f98d69e 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -870,6 +870,10 @@
return self._from_parsed_parts(self._drv, self._root,
self._parts[:-1] + [name])
+ def with_stem(self, stem):
+ """Return a new path with the stem changed."""
+ return self.with_name(stem + self.suffix)
+
def with_suffix(self, suffix):
"""Return a new path with the file suffix changed. If the path
has no suffix, add given suffix. If the given suffix is an empty
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index 8b19cff..1589282 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -559,6 +559,23 @@
self.assertRaises(ValueError, P('a/b').with_name, 'c/')
self.assertRaises(ValueError, P('a/b').with_name, 'c/d')
+ def test_with_stem_common(self):
+ P = self.cls
+ self.assertEqual(P('a/b').with_stem('d'), P('a/d'))
+ self.assertEqual(P('/a/b').with_stem('d'), P('/a/d'))
+ self.assertEqual(P('a/b.py').with_stem('d'), P('a/d.py'))
+ self.assertEqual(P('/a/b.py').with_stem('d'), P('/a/d.py'))
+ self.assertEqual(P('/a/b.tar.gz').with_stem('d'), P('/a/d.gz'))
+ self.assertEqual(P('a/Dot ending.').with_stem('d'), P('a/d'))
+ self.assertEqual(P('/a/Dot ending.').with_stem('d'), P('/a/d'))
+ self.assertRaises(ValueError, P('').with_stem, 'd')
+ self.assertRaises(ValueError, P('.').with_stem, 'd')
+ self.assertRaises(ValueError, P('/').with_stem, 'd')
+ self.assertRaises(ValueError, P('a/b').with_stem, '')
+ self.assertRaises(ValueError, P('a/b').with_stem, '/c')
+ self.assertRaises(ValueError, P('a/b').with_stem, 'c/')
+ self.assertRaises(ValueError, P('a/b').with_stem, 'c/d')
+
def test_with_suffix_common(self):
P = self.cls
self.assertEqual(P('a/b').with_suffix('.gz'), P('a/b.gz'))
@@ -1014,6 +1031,20 @@
self.assertRaises(ValueError, P('c:a/b').with_name, 'd:/e')
self.assertRaises(ValueError, P('c:a/b').with_name, '//My/Share')
+ def test_with_stem(self):
+ P = self.cls
+ self.assertEqual(P('c:a/b').with_stem('d'), P('c:a/d'))
+ self.assertEqual(P('c:/a/b').with_stem('d'), P('c:/a/d'))
+ self.assertEqual(P('c:a/Dot ending.').with_stem('d'), P('c:a/d'))
+ self.assertEqual(P('c:/a/Dot ending.').with_stem('d'), P('c:/a/d'))
+ self.assertRaises(ValueError, P('c:').with_stem, 'd')
+ self.assertRaises(ValueError, P('c:/').with_stem, 'd')
+ self.assertRaises(ValueError, P('//My/Share').with_stem, 'd')
+ self.assertRaises(ValueError, P('c:a/b').with_stem, 'd:')
+ self.assertRaises(ValueError, P('c:a/b').with_stem, 'd:e')
+ self.assertRaises(ValueError, P('c:a/b').with_stem, 'd:/e')
+ self.assertRaises(ValueError, P('c:a/b').with_stem, '//My/Share')
+
def test_with_suffix(self):
P = self.cls
self.assertEqual(P('c:a/b').with_suffix('.gz'), P('c:a/b.gz'))
diff --git a/Misc/NEWS.d/next/Library/2020-04-19-14-16-43.bpo-40148.pDZR6V.rst b/Misc/NEWS.d/next/Library/2020-04-19-14-16-43.bpo-40148.pDZR6V.rst
new file mode 100644
index 0000000..02a5f9d
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-04-19-14-16-43.bpo-40148.pDZR6V.rst
@@ -0,0 +1 @@
+Added :meth:`pathlib.Path.with_stem()` to create a new Path with the stem replaced.
\ No newline at end of file