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