inspect.signature: Support classes without user-defined __init__/__new__ #20308
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 9436e35..2211b8d 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -1561,6 +1561,17 @@
init = _get_user_defined_method(obj, '__init__')
if init is not None:
sig = signature(init)
+
+ if sig is None:
+ if type in obj.__mro__:
+ # 'obj' is a metaclass without user-defined __init__
+ # or __new__. Return a signature of 'type' builtin.
+ return signature(type)
+ else:
+ # We have a class (not metaclass), but no user-defined
+ # __init__ or __new__ for it
+ return signature(object)
+
elif not isinstance(obj, _NonUserDefinedCallables):
# An object with __call__
# We also check that the 'obj' is not an instance of