Subclass from os.PathLike

Author: barneygale

Lib/os.py

@@ -1079,6 +1079,8 @@ class PathLike(abc.ABC):
 
  """Abstract base class for implementing the file system path protocol."""
 
+ __slots__ = ()
+
  @abc.abstractmethod
  def __fspath__(self):
  """Return the file system path representation of the object."""

Lib/pathlib.py

@@ -666,7 +666,7 @@ def match(self, path_pattern, *, case_sensitive=None):
  return True
 
 
-class PurePath(_BasePurePath):
+class PurePath(_BasePurePath, os.PathLike):
  """Base class for manipulating paths without I/O.
 
  PurePath represents a filesystem path and offers operations which
@@ -716,11 +716,6 @@ def as_uri(self):
  return prefix + urlquote_from_bytes(os.fsencode(path))
 
 
-# Can't subclass os.PathLike from PurePath and keep the constructor
-# optimizations in PurePath.__slots__.
-os.PathLike.register(PurePath)
-
-
 class PurePosixPath(PurePath):
  """PurePath subclass for non-Windows systems.
 

Lib/test/test_os.py

@@ -4640,6 +4640,13 @@ class A(os.PathLike):
  def test_pathlike_class_getitem(self):
  self.assertIsInstance(os.PathLike[bytes], types.GenericAlias)
 
+ def test_pathlike_subclass_slots(self):
+ class A(os.PathLike):
+ __slots__ = ()
+ def __fspath__(self):
+ return ''
+ self.assertFalse(hasattr(A(), '__dict__'))
+
 
 class TimesTests(unittest.TestCase):
  def test_times(self):