bpo-30149: Fix partialmethod without explicit self parameter (#1308) (#1662)
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 2894672..3317f58 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -2241,11 +2241,16 @@
sigcls=sigcls)
sig = _signature_get_partial(wrapped_sig, partialmethod, (None,))
-
first_wrapped_param = tuple(wrapped_sig.parameters.values())[0]
- new_params = (first_wrapped_param,) + tuple(sig.parameters.values())
-
- return sig.replace(parameters=new_params)
+ if first_wrapped_param.kind is Parameter.VAR_POSITIONAL:
+ # First argument of the wrapped callable is `*args`, as in
+ # `partialmethod(lambda *args)`.
+ return sig
+ else:
+ sig_params = tuple(sig.parameters.values())
+ assert first_wrapped_param is not sig_params[0]
+ new_params = (first_wrapped_param,) + sig_params
+ return sig.replace(parameters=new_params)
if isfunction(obj) or _signature_is_functionlike(obj):
# If it's a pure Python function, or an object that is duck type
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 37e4511..facf040 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1989,6 +1989,41 @@
('kwargs', ..., int, "var_keyword")),
...))
+ def test_signature_without_self(self):
+ def test_args_only(*args): # NOQA
+ pass
+
+ def test_args_kwargs_only(*args, **kwargs): # NOQA
+ pass
+
+ class A:
+ @classmethod
+ def test_classmethod(*args): # NOQA
+ pass
+
+ @staticmethod
+ def test_staticmethod(*args): # NOQA
+ pass
+
+ f1 = functools.partialmethod((test_classmethod), 1)
+ f2 = functools.partialmethod((test_args_only), 1)
+ f3 = functools.partialmethod((test_staticmethod), 1)
+ f4 = functools.partialmethod((test_args_kwargs_only),1)
+
+ self.assertEqual(self.signature(test_args_only),
+ ((('args', ..., ..., 'var_positional'),), ...))
+ self.assertEqual(self.signature(test_args_kwargs_only),
+ ((('args', ..., ..., 'var_positional'),
+ ('kwargs', ..., ..., 'var_keyword')), ...))
+ self.assertEqual(self.signature(A.f1),
+ ((('args', ..., ..., 'var_positional'),), ...))
+ self.assertEqual(self.signature(A.f2),
+ ((('args', ..., ..., 'var_positional'),), ...))
+ self.assertEqual(self.signature(A.f3),
+ ((('args', ..., ..., 'var_positional'),), ...))
+ self.assertEqual(self.signature(A.f4),
+ ((('args', ..., ..., 'var_positional'),
+ ('kwargs', ..., ..., 'var_keyword')), ...))
@cpython_only
@unittest.skipIf(MISSING_C_DOCSTRINGS,
"Signature information for builtins requires docstrings")