Merge branch 'main' into dataclass-lazy-inspect

Author: danielhollas

Doc/library/datetime.rst

@@ -2534,8 +2534,8 @@ requires, and these work on all supported platforms.
 |  ``%d``   | Day of the month as a          | 01, 02, ..., 31        | \(9)  |
 |           | zero-padded decimal number.    |                        |       |
 +-----------+--------------------------------+------------------------+-------+
-|  ``%D``   | Equivalent to ``%m/%d/%y``.    | 11/10/2025             | \(9), |
-|           |                                |                        | \(0)  |
+|  ``%D``   | Equivalent to ``%m/%d/%y``.    | 11/28/25               | \(9)  |
+|           |                                |                        |       |
 +-----------+--------------------------------+------------------------+-------+
 |  ``%e``   | The day of the month as a      | ␣1, ␣2, ..., 31        |       |
 |           | space-padded decimal number.   |                        |       |
@@ -2676,7 +2676,7 @@ differences between platforms in handling of unsupported format specifiers.
    ``%:z`` was added for :meth:`~.datetime.strftime`.
 
 .. versionadded:: 3.15
-   ``%:z`` and ``%F`` were added for :meth:`~.datetime.strptime`.
+   ``%:z``, ``%F``, and ``%D`` were added for :meth:`~.datetime.strptime`.
 
 Technical Detail
 ^^^^^^^^^^^^^^^^

Lib/_ast_unparse.py

@@ -239,11 +239,11 @@ def visit_NamedExpr(self, node):
             self.traverse(node.value)
 
     def visit_Import(self, node):
-        self.fill("import ")
+        self.fill("lazy import " if node.is_lazy else "import ")
         self.interleave(lambda: self.write(", "), self.traverse, node.names)
 
     def visit_ImportFrom(self, node):
-        self.fill("from ")
+        self.fill("lazy from " if node.is_lazy else "from ")
         self.write("." * (node.level or 0))
         if node.module:
             self.write(node.module)

Lib/_strptime.py

@@ -418,6 +418,7 @@ def __init__(self, locale_time=None):
         mapping['W'] = mapping['U'].replace('U', 'W')
 
         base.__init__(mapping)
+        base.__setitem__('D', self.pattern('%m/%d/%y'))
         base.__setitem__('F', self.pattern('%Y-%m-%d'))
         base.__setitem__('T', self.pattern('%H:%M:%S'))
         base.__setitem__('R', self.pattern('%H:%M'))

Lib/test/datetimetester.py

@@ -2200,6 +2200,13 @@ def test_strptime_F_format(self):
             self.theclass.strptime(test_date, "%Y-%m-%d")
         )
 
+    def test_strptime_D_format(self):
+        test_date = "11/28/25"
+        self.assertEqual(
+            self.theclass.strptime(test_date, "%D"),
+            self.theclass.strptime(test_date, "%m/%d/%y")
+        )
+
 
 #############################################################################
 # datetime tests

Lib/test/pickletester.py

@@ -3202,6 +3202,7 @@ def test_builtin_exceptions(self):
             'ExceptionGroup': (3, 11),
             '_IncompleteInputError': (3, 13),
             'PythonFinalizationError': (3, 13),
+            'ImportCycleError': (3, 15),
         }
         for t in builtins.__dict__.values():
             if isinstance(t, type) and issubclass(t, BaseException):
@@ -3228,6 +3229,7 @@ def test_builtin_functions(self):
             'breakpoint': (3, 7),
             'aiter': (3, 10),
             'anext': (3, 10),
+            '__lazy_import__': (3, 15),
         }
         for t in builtins.__dict__.values():
             if isinstance(t, types.BuiltinFunctionType):

Lib/test/test_strptime.py

@@ -286,7 +286,7 @@ def test_ValueError(self):
     def test_strptime_exception_context(self):
         # check that this doesn't chain exceptions needlessly (see #17572)
         with self.assertRaises(ValueError) as e:
-            _strptime._strptime_time('', '%D')
+            _strptime._strptime_time('', '%!')
         self.assertTrue(e.exception.__suppress_context__)
         # additional check for stray % branch
         with self.assertRaises(ValueError) as e:
@@ -663,6 +663,13 @@ def test_strptime_T_format(self):
             time.strptime(test_time, "%H:%M:%S")
         )
 
+    def test_strptime_D_format(self):
+        test_date = "11/28/25"
+        self.assertEqual(
+            time.strptime(test_date, "%D"),
+            time.strptime(test_date, "%m/%d/%y")
+        )
+
 class Strptime12AMPMTests(unittest.TestCase):
     """Test a _strptime regression in '%I %p' at 12 noon (12 PM)"""
 

Lib/test/test_time.py

@@ -358,7 +358,7 @@ def test_strptime(self):
         # Should be able to go round-trip from strftime to strptime without
         # raising an exception.
         tt = time.gmtime(self.t)
-        for directive in ('a', 'A', 'b', 'B', 'c', 'd', 'F', 'H', 'I',
+        for directive in ('a', 'A', 'b', 'B', 'c', 'd', 'D', 'F', 'H', 'I',
                           'j', 'm', 'M', 'p', 'S', 'T',
                           'U', 'w', 'W', 'x', 'X', 'y', 'Y', 'Z', '%'):
             format = '%' + directive
@@ -379,7 +379,7 @@ def test_strptime_bytes(self):
     def test_strptime_exception_context(self):
         # check that this doesn't chain exceptions needlessly (see #17572)
         with self.assertRaises(ValueError) as e:
-            time.strptime('', '%D')
+            time.strptime('', '%!')
         self.assertTrue(e.exception.__suppress_context__)
         # additional check for stray % branch
         with self.assertRaises(ValueError) as e:

Misc/NEWS.d/next/Library/2026-02-14-14-56-44.gh-issue-140715.AbSheM.rst

@@ -0,0 +1 @@
+Add ``'%D'`` support to :meth:`~datetime.datetime.strptime`.