Issue 24298: Fix signature() to properly unwrap wrappers around bound methods
diff --git a/Lib/inspect.py b/Lib/inspect.py
index a91f749..49e66ce 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -1911,6 +1911,14 @@
# Was this function wrapped by a decorator?
if follow_wrapper_chains:
obj = unwrap(obj, stop=(lambda f: hasattr(f, "__signature__")))
+ if isinstance(obj, types.MethodType):
+ # If the unwrapped object is a *method*, we might want to
+ # skip its first parameter (self).
+ # See test_signature_wrapped_bound_method for details.
+ return _signature_internal(
+ obj,
+ follow_wrapper_chains=follow_wrapper_chains,
+ skip_bound_arg=skip_bound_arg)
try:
sig = obj.__signature__
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 8d92f82..58a6cd2 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1939,6 +1939,19 @@
with self.assertRaisesRegex(ValueError, 'invalid method signature'):
self.signature(Test())
+ def test_signature_wrapped_bound_method(self):
+ # Issue 24298
+ class Test:
+ def m1(self, arg1, arg2=1) -> int:
+ pass
+ @functools.wraps(Test().m1)
+ def m1d(*args, **kwargs):
+ pass
+ self.assertEqual(self.signature(m1d),
+ ((('arg1', ..., ..., "positional_or_keyword"),
+ ('arg2', 1, ..., "positional_or_keyword")),
+ int))
+
def test_signature_on_classmethod(self):
class Test:
@classmethod