gh-57179: Add note on symlinks for os.walk (#94799)

Author: slateny

Doc/library/os.rst

@@ -3222,7 +3222,8 @@ features:
    filenames)``.
 
    *dirpath* is a string, the path to the directory.  *dirnames* is a list of the
-   names of the subdirectories in *dirpath* (excluding ``'.'`` and ``'..'``).
+   names of the subdirectories in *dirpath* (including symlinks to directories,
+   and excluding ``'.'`` and ``'..'``).
    *filenames* is a list of the names of the non-directory files in *dirpath*.
    Note that the names in the lists contain no path components.  To get a full path
    (which begins with *top*) to a file or directory in *dirpath*, do

Lib/os.py

@@ -288,7 +288,8 @@ def walk(top, topdown=True, onerror=None, followlinks=False):
         dirpath, dirnames, filenames
 
     dirpath is a string, the path to the directory.  dirnames is a list of
-    the names of the subdirectories in dirpath (excluding '.' and '..').
+    the names of the subdirectories in dirpath (including symlinks to directories,
+    and excluding '.' and '..').
     filenames is a list of the names of the non-directory files in dirpath.
     Note that the names in the lists are just names, with no path components.
     To get a full path (which begins with top) to a file or directory in