gh-101196: Make isdir/isfile/exists faster on Windows (GH-101324)

Co-authored-by: Eryk Sun <eryksun@gmail.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/Lib/genericpath.py b/Lib/genericpath.py
index ce36451..1bd5b38 100644
--- a/Lib/genericpath.py
+++ b/Lib/genericpath.py
@@ -7,7 +7,7 @@ import os
 import stat
 
 __all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
-           'getsize', 'isdir', 'isfile', 'samefile', 'sameopenfile',
+           'getsize', 'isdir', 'isfile', 'islink', 'samefile', 'sameopenfile',
            'samestat']
 
 
@@ -45,6 +45,18 @@ def isdir(s):
     return stat.S_ISDIR(st.st_mode)
 
 
+# Is a path a symbolic link?
+# This will always return false on systems where os.lstat doesn't exist.
+
+def islink(path):
+    """Test whether a path is a symbolic link"""
+    try:
+        st = os.lstat(path)
+    except (OSError, ValueError, AttributeError):
+        return False
+    return stat.S_ISLNK(st.st_mode)
+
+
 def getsize(filename):
     """Return the size of a file, reported by os.stat()."""
     return os.stat(filename).st_size