GH-132566: Add pathlib.Path.info.is_junction()

Doc/library/pathlib.rst

@@ -1210,9 +1210,10 @@ Querying file type and status
    any filesystem queries.
 
    To fetch up-to-date information, it's best to call :meth:`Path.is_dir`,
-   :meth:`~Path.is_file` and :meth:`~Path.is_symlink` rather than methods of
-   this attribute. There is no way to reset the cache; instead you can create
-   a new path object with an empty info cache via ``p = Path(p)``.
+   :meth:`~Path.is_file`, :meth:`~Path.is_symlink`, and
+   :meth:`~Path.is_junction` rather than methods of this attribute. There is
+   no way to reset the cache; instead you can create a new path object with an
+   empty info cache via ``p = Path(p)``.
 
    .. versionadded:: 3.14
 
@@ -1989,3 +1990,8 @@ The :mod:`pathlib.types` module provides types for static type checking.
       Return ``True`` if the path is a symbolic link (even if broken); return
       ``False`` if the path is a directory or any kind of file, or if it
       doesn't exist.
+
+   .. method:: is_junction()
+
+      Return ``True`` if the path is a junction; return ``False`` for any
+      other type of file. Currently only Windows supports junctions.

Lib/pathlib/__init__.py

@@ -1059,9 +1059,9 @@ def _delete(self):
         """
         Delete this file or directory (including all sub-directories).
         """
-        if self.is_symlink() or self.is_junction():
+        if self.info.is_symlink() or self.info.is_junction():
             self.unlink()
-        elif self.is_dir():
+        elif self.info.is_dir():
             # Lazy import to improve module import time
             import shutil
             shutil.rmtree(self)

Lib/pathlib/_os.py

@@ -390,7 +390,7 @@ def _xattrs(self, *, follow_symlinks=True):
 class _WindowsPathInfo(_PathInfoBase):
     """Implementation of pathlib.types.PathInfo that provides status
     information for Windows paths. Don't try to construct it yourself."""
-    __slots__ = ('_exists', '_is_dir', '_is_file', '_is_symlink')
+    __slots__ = ('_exists', '_is_dir', '_is_file', '_is_symlink', '_is_junction')
 
     def exists(self, *, follow_symlinks=True):
         """Whether this path exists."""
@@ -442,6 +442,14 @@ def is_symlink(self):
             self._is_symlink = os.path.islink(self._path)
             return self._is_symlink
 
+    def is_junction(self):
+        """Whether this path is a junction."""
+        try:
+            return self._is_junction
+        except AttributeError:
+            self._is_junction = os.path.isjunction(self._path)
+            return self._is_junction
+
 
 class _PosixPathInfo(_PathInfoBase):
     """Implementation of pathlib.types.PathInfo that provides status
@@ -476,6 +484,10 @@ def is_symlink(self):
             return False
         return S_ISLNK(st.st_mode)
 
+    def is_junction(self):
+        """Whether this path is a junction."""
+        return False
+
 
 PathInfo = _WindowsPathInfo if os.name == 'nt' else _PosixPathInfo
 
@@ -524,3 +536,10 @@ def is_symlink(self):
             return self._entry.is_symlink()
         except OSError:
             return False
+
+    def is_junction(self):
+        """Whether this path is a junction."""
+        try:
+            return self._entry.is_junction()
+        except OSError:
+            return False

Lib/pathlib/types.py

@@ -57,6 +57,7 @@ def exists(self, *, follow_symlinks: bool = True) -> bool: ...
     def is_dir(self, *, follow_symlinks: bool = True) -> bool: ...
     def is_file(self, *, follow_symlinks: bool = True) -> bool: ...
     def is_symlink(self) -> bool: ...
+    def is_junction(self) -> bool: ...
 
 
 class _JoinablePath(ABC):

Lib/test/test_pathlib/support/local_path.py

@@ -94,14 +94,15 @@ class LocalPathInfo(PathInfo):
     """
     Simple implementation of PathInfo for a local path
     """
-    __slots__ = ('_path', '_exists', '_is_dir', '_is_file', '_is_symlink')
+    __slots__ = ('_path', '_exists', '_is_dir', '_is_file', '_is_symlink', '_is_junction')
 
     def __init__(self, path):
         self._path = str(path)
         self._exists = None
         self._is_dir = None
         self._is_file = None
         self._is_symlink = None
+        self._is_junction = None
 
     def exists(self, *, follow_symlinks=True):
         """Whether this path exists."""
@@ -133,6 +134,11 @@ def is_symlink(self):
             self._is_symlink = os.path.islink(self._path)
         return self._is_symlink
 
+    def is_junction(self):
+        if self._is_junction is None:
+            self._is_junction = os.path.isjunction(self._path)
+        return self._is_junction
+
 
 class ReadableLocalPath(_ReadablePath, LexicalPath):
     """

Lib/test/test_pathlib/support/zip_path.py

@@ -107,6 +107,9 @@ def is_file(self, follow_symlinks=True):
     def is_symlink(self):
         return False
 
+    def is_junction(self):
+        return False
+
     def resolve(self):
         return self
 

Lib/test/test_pathlib/test_pathlib.py

@@ -2557,6 +2557,13 @@ def test_info_is_symlink_caching(self):
         q.unlink()
         self.assertTrue(q.info.is_symlink())
 
+    @needs_windows
+    def test_info_is_junction(self):
+        p = self.cls(self.base, 'fileA')
+        with mock.patch.object(os.path, 'isjunction'):
+            self.assertFalse(p.info.is_junction())
+            os.path.isjunction.assert_called_once_with(p)
+
     def test_stat(self):
         statA = self.cls(self.base).joinpath('fileA').stat()
         statB = self.cls(self.base).joinpath('dirB', 'fileB').stat()

Lib/test/test_pathlib/test_read.py

@@ -301,6 +301,15 @@ def test_info_is_symlink(self):
         self.assertFalse((p / 'fileA\udfff').info.is_symlink())
         self.assertFalse((p / 'fileA\x00').info.is_symlink())
 
+    def test_info_is_junction(self):
+        p = self.root
+        self.assertFalse((p / 'fileA').info.is_junction())
+        self.assertFalse((p / 'dirA').info.is_junction())
+        self.assertFalse((p / 'non-existing').info.is_junction())
+        self.assertFalse((p / 'fileA' / 'bah').info.is_junction())
+        self.assertFalse((p / 'fileA\udfff').info.is_junction())
+        self.assertFalse((p / 'fileA\x00').info.is_junction())
+
 
 class ZipPathReadTest(ReadTestBase, unittest.TestCase):
     ground = ZipPathGround(ReadableZipPath)

Misc/NEWS.d/next/Library/2025-04-15-20-30-05.gh-issue-132566.IMeNM5.rst

@@ -0,0 +1,2 @@
+Add :meth:`pathlib.types.PathInfo.is_junction` method, which returns true if
+the path is a Windows junction.