gh-88569: add `ntpath.isreserved()` (#95486)

Add `ntpath.isreserved()`, which identifies reserved pathnames such as "NUL", "AUX" and "CON".

Deprecate `pathlib.PurePath.is_reserved()`.

---------

Co-authored-by: Eryk Sun <eryksun@gmail.com>
Co-authored-by: Brett Cannon <brett@python.org>
Co-authored-by: Steve Dower <steve.dower@microsoft.com>

1 files changed, 6 insertions, 42 deletions

diff --git a/Lib/test/test_pathlib/test_pathlib.py b/Lib/test/test_pathlib/test_pathlib.py
index bdbe923..2da3afdd 100644
--- a/Lib/test/test_pathlib/test_pathlib.py
+++ b/Lib/test/test_pathlib/test_pathlib.py
@@ -349,6 +349,12 @@ class PurePathTest(test_pathlib_abc.DummyPurePathTest):
         with self.assertWarns(DeprecationWarning):
             p.is_relative_to('a', 'b')
 
+    def test_is_reserved_deprecated(self):
+        P = self.cls
+        p = P('a/b')
+        with self.assertWarns(DeprecationWarning):
+            p.is_reserved()
+
     def test_match_empty(self):
         P = self.cls
         self.assertRaises(ValueError, P('a').match, '')
@@ -414,13 +420,6 @@ class PurePosixPathTest(PurePathTest):
         self.assertTrue(P('//a').is_absolute())
         self.assertTrue(P('//a/b').is_absolute())
 
-    def test_is_reserved(self):
-        P = self.cls
-        self.assertIs(False, P('').is_reserved())
-        self.assertIs(False, P('/').is_reserved())
-        self.assertIs(False, P('/foo/bar').is_reserved())
-        self.assertIs(False, P('/dev/con/PRN/NUL').is_reserved())
-
     def test_join(self):
         P = self.cls
         p = P('//a')
@@ -1082,41 +1081,6 @@ class PureWindowsPathTest(PurePathTest):
         self.assertEqual(p / P('./dd:s'), P('C:/a/b/dd:s'))
         self.assertEqual(p / P('E:d:s'), P('E:d:s'))
 
-    def test_is_reserved(self):
-        P = self.cls
-        self.assertIs(False, P('').is_reserved())
-        self.assertIs(False, P('/').is_reserved())
-        self.assertIs(False, P('/foo/bar').is_reserved())
-        # UNC paths are never reserved.
-        self.assertIs(False, P('//my/share/nul/con/aux').is_reserved())
-        # Case-insensitive DOS-device names are reserved.
-        self.assertIs(True, P('nul').is_reserved())
-        self.assertIs(True, P('aux').is_reserved())
-        self.assertIs(True, P('prn').is_reserved())
-        self.assertIs(True, P('con').is_reserved())
-        self.assertIs(True, P('conin$').is_reserved())
-        self.assertIs(True, P('conout$').is_reserved())
-        # COM/LPT + 1-9 or + superscript 1-3 are reserved.
-        self.assertIs(True, P('COM1').is_reserved())
-        self.assertIs(True, P('LPT9').is_reserved())
-        self.assertIs(True, P('com\xb9').is_reserved())
-        self.assertIs(True, P('com\xb2').is_reserved())
-        self.assertIs(True, P('lpt\xb3').is_reserved())
-        # DOS-device name mataching ignores characters after a dot or
-        # a colon and also ignores trailing spaces.
-        self.assertIs(True, P('NUL.txt').is_reserved())
-        self.assertIs(True, P('PRN  ').is_reserved())
-        self.assertIs(True, P('AUX  .txt').is_reserved())
-        self.assertIs(True, P('COM1:bar').is_reserved())
-        self.assertIs(True, P('LPT9   :bar').is_reserved())
-        # DOS-device names are only matched at the beginning
-        # of a path component.
-        self.assertIs(False, P('bar.com9').is_reserved())
-        self.assertIs(False, P('bar.lpt9').is_reserved())
-        # Only the last path component matters.
-        self.assertIs(True, P('c:/baz/con/NUL').is_reserved())
-        self.assertIs(False, P('c:/NUL/con/baz').is_reserved())
-
 
 class PurePathSubclassTest(PurePathTest):
     class cls(pathlib.PurePath):