gh-108901: Deprecate inspect.getargs, slate it for removal in 3.15

Doc/whatsnew/3.13.rst

@@ -581,6 +581,13 @@ Pending Removal in Python 3.15
   All arguments will be removed from :func:`threading.RLock` in Python 3.15.
   (Contributed by Nikita Sobolev in :gh:`102029`.)
 
+* The undocumented function ``inspect.getargs`` is deprecated in Python 3.13
+  and slated for removal in Python 3.15. :func:`inspect.signature` is the most
+  accurate way to obtain the signature of a callable. If you only have access
+  to a code object, however, ``inspect.signature(types.FunctionType(co, {}))``
+  can be used as a direct replacement for ``inspect.getargs()``.
+  (Contributed by Nikita Sobolev in :gh:`108901`.)
+
 Pending Removal in Python 3.16
 ------------------------------
 

Lib/inspect.py

@@ -1363,7 +1363,23 @@ def getargs(co):
     Three things are returned: (args, varargs, varkw), where
     'args' is the list of argument names. Keyword-only arguments are
     appended. 'varargs' and 'varkw' are the names of the * and **
-    arguments or None."""
+    arguments or None.
+
+    Deprecated in Python 3.13; slated for removal in Python 3.15.
+    ``inspect.signature`` is the most accurate way to obtain the signature
+    of a callable. If you only have access to a code object, however,
+    ``inspect.signature(types.FunctionType(co, {}))`` can be used as a
+    direct replacement for ``inspect.getargs()``.
+    """
+    import warnings
+    warnings._deprecated(
+        "getargs",
+        (
+            "{name!r} is deprecated and slated for removal in Python {remove}; "
+            "use `inspect.signature` instead."
+        ),
+        remove=(3, 15),
+    )
     if not iscode(co):
         raise TypeError('{!r} is not a code object'.format(co))
 
@@ -1489,7 +1505,10 @@ def getargvalues(frame):
     'args' is a list of the argument names.
     'varargs' and 'varkw' are the names of the * and ** arguments or None.
     'locals' is the locals dictionary of the given frame."""
-    args, varargs, varkw = getargs(frame.f_code)
+    import warnings
+    with warnings.catch_warnings():
+        warnings.simplefilter('ignore', category=DeprecationWarning)
+        args, varargs, varkw = getargs(frame.f_code)
     return ArgInfo(args, varargs, varkw, frame.f_locals)
 
 def formatannotation(annotation, base_module=None):

Lib/test/test_inspect/test_inspect.py

@@ -5022,6 +5022,17 @@ def f():
         self.assertIn(expected, output)
 
 
+class TestGetArgs(unittest.TestCase):
+    def test_getargs_deprecated(self):
+        import re
+
+        def func(a, b): ...
+
+        with self.assertWarnsRegex(
+            DeprecationWarning,
+            re.escape("'getargs' is deprecated and slated for removal in Python 3.15"),
+        ):
+            inspect.getargs(func.__code__)
 
 
 if __name__ == "__main__":

Misc/NEWS.d/next/Library/2023-11-20-12-31-14.gh-issue-108901.abVgVe.rst

@@ -0,0 +1,6 @@
+The undocumented function ``inspect.getargs`` is deprecated in
+Python 3.13 and slated for removal in Python 3.15.
+:func:`inspect.signature` is the most accurate way to obtain the signature
+of a callable. If you only have access to a code object, however,
+``inspect.signature(types.FunctionType(co, {}))`` can be used as a
+direct replacement for ``inspect.getargs()``.