bpo-42367: Restore os.makedirs() ability to apply *mode* recursively

Allow os.makedirs() to apply the *mode* argument to any intermediate
directories that are created.

Doc/library/os.rst

@@ -2055,7 +2055,8 @@ features:
       Accepts a :term:`path-like object`.
 
 
-.. function:: makedirs(name, mode=0o777, exist_ok=False)
+.. function:: makedirs(name, mode=0o777, exist_ok=False, *, \
+                       recursive_mode=False)
 
    .. index::
       single: directory; creating
@@ -2073,6 +2074,9 @@ features:
    If *exist_ok* is ``False`` (the default), an :exc:`FileExistsError` is
    raised if the target directory already exists.
 
+   If *recursive_mode* is ``True``, the *mode* argument will affect the file
+   permission bits of any newly-created, intermediate-level directories.
+
    .. note::
 
       :func:`makedirs` will become confused if the path elements to create
@@ -2099,6 +2103,9 @@ features:
       The *mode* argument no longer affects the file permission bits of
       newly-created intermediate-level directories.
 
+   .. versionadded:: 3.10
+      The *recursive_mode* parameter.
+
 
 .. function:: mkfifo(path, mode=0o666, *, dir_fd=None)
 

Doc/whatsnew/3.10.rst

@@ -259,6 +259,9 @@ descriptors without copying between kernel address space and user
 address space, where one of the file descriptors must refer to a
 pipe. (Contributed by Pablo Galindo in :issue:`41625`.)
 
+The :func:`os.makedirs` function now has a *recursive_mode* parameter.
+(Contributed by Zackery Spytz in :issue:`42367`.)
+
 pathlib
 -------
 

Lib/os.py

@@ -197,14 +197,16 @@ SEEK_END = 2
 # Super directory utilities.
 # (Inspired by Eric Raymond; the doc strings are mostly his)
 
-def makedirs(name, mode=0o777, exist_ok=False):
-    """makedirs(name [, mode=0o777][, exist_ok=False])
+def makedirs(name, mode=0o777, exist_ok=False, *, recursive_mode=False):
+    """makedirs(name [, mode=0o777][, exist_ok=False][, recursive_mode=False])
 
     Super-mkdir; create a leaf directory and all intermediate ones.  Works like
     mkdir, except that any intermediate path segment (not just the rightmost)
     will be created if it does not exist. If the target directory already
     exists, raise an OSError if exist_ok is False. Otherwise no exception is
-    raised.  This is recursive.
+    raised.  If recursive_mode is True, the mode argument will affect the file
+    permission bits of any newly-created, intermediate-level directories.  This
+    is recursive.
 
     """
     head, tail = path.split(name)
@@ -212,6 +214,10 @@ def makedirs(name, mode=0o777, exist_ok=False):
         head, tail = path.split(head)
     if head and tail and not path.exists(head):
         try:
+            if recursive_mode:
+                makedirs(head, mode=mode, exist_ok=exist_ok,
+                         recursive_mode=True)
+            else:
                 makedirs(head, exist_ok=exist_ok)
         except FileExistsError:
             # Defeats race condition when another thread created the path

Lib/test/test_os.py

@@ -1572,16 +1572,19 @@ class MakedirTests(unittest.TestCase):
         os.makedirs(path)
 
     def test_mode(self):
-        with os_helper.temp_umask(0o002):
-            base = os_helper.TESTFN
-            parent = os.path.join(base, 'dir1')
+        parent = os.path.join(os_helper.TESTFN, 'dir1')
         path = os.path.join(parent, 'dir2')
-            os.makedirs(path, 0o555)
+        with os_helper.temp_umask(0o002):
+            for mode, recursive_mode, path_mode, parent_mode in \
+                    (0o555, False, 0o555, 0o775), (0o770, True, 0o770, 0o770):
+                os.makedirs(path, mode, recursive_mode=recursive_mode)
                 self.assertTrue(os.path.exists(path))
                 self.assertTrue(os.path.isdir(path))
                 if os.name != 'nt':
-                self.assertEqual(os.stat(path).st_mode & 0o777, 0o555)
-                self.assertEqual(os.stat(parent).st_mode & 0o777, 0o775)
+                    self.assertEqual(os.stat(path).st_mode & 0o777, path_mode)
+                    self.assertEqual(os.stat(parent).st_mode & 0o777,
+                                     parent_mode)
+                shutil.rmtree(parent)
 
     def test_exist_ok_existing_directory(self):
         path = os.path.join(os_helper.TESTFN, 'dir1')

Misc/NEWS.d/next/Library/2020-12-22-16-55-59.bpo-42367.IGICm2.rst

@@ -0,0 +1 @@
+The :func:`os.makedirs` function now has a *recursive_mode* parameter.