>>> import inspect >>> class C:	def meth(*args): pass >>> str(inspect.signature(C.meth)) '(*args)' >>> c=C() >>> str(s=inspect.signature(c.meth)) '()' *args should have been left in even for the bound method, as idlelib calltips do. Since '*' is not a word character, idlelib.Calltips._first_param = re.compile('(?<=\()\w*\,?\s*') does not see '*args' as a substring to be deleted with argspec = _first_param.sub("", argspec) The same comment applies to def meth2(**kwds): pass even though calling the bound method would fail.

Yury, can you look in to this? I have been modifying inspect.signature, but (almost) exclusively in from_builtin. If this is my fault I'll be happy to fix it.

There does not appear to be a test for this. If so, this case may not have ever worked right. Here is the only failure at the moment (which should also be fixed). F:\Python\dev>4\py34\pcbuild\python_d.exe -m test test_inspect [1/1] test_inspect test test_inspect failed -- Traceback (most recent call last): File "F:\Python\dev\4\py34\lib\test\test_inspect.py", line 1623, in test_signature_on_builtins test_callable(type) File "F:\Python\dev\4\py34\lib\test\test_inspect.py", line 1604, in test_callable signature = inspect.signature(o) File "F:\Python\dev\4\py34\lib\inspect.py", line 1555, in signature raise ValueError('callable {!r} is not supported by signature'.format(obj)) ValueError: callable <class 'type'> is not supported by signature

I just tried it in 3.3 (3.3.1rc1) and it had the same problem.

Yes, that's s bug. I'll take a look tomorrow.

Sorry, I should have said that I tried repository versions of both 3.3 and 3.4.

Patch is attached, please review. Should we commit this to 3.3 too?

New changeset 3544827d42e6 by Yury Selivanov in branch 'default': inspect.signature: Handle bound methods with '(*args)' signature correctly #20401 http://hg.python.org/cpython/rev/3544827d42e6

Committed. Thank you, Terry.

Is there any reason that the second case Terry provide still will failed with ValueError? class C: def meth2(**kwds): pass ip.signature(C().meth2) Traceback (most recent call last): File "/home/linux/Python/cpython/Lib/idlelib/idle_test/test_calltips.py", line 139, in test_starred_parameter self.assertEqual(signature(meth), mtip) File "/home/linux/Python/cpython/Lib/idlelib/calltips.py", line 149, in get_argspec argspec = str(inspect.signature(fob)) File "/home/linux/Python/cpython/Lib/inspect.py", line 3028, in signature return Signature.from_callable(obj, follow_wrapped=follow_wrapped) File "/home/linux/Python/cpython/Lib/inspect.py", line 2778, in from_callable follow_wrapper_chains=follow_wrapped) File "/home/linux/Python/cpython/Lib/inspect.py", line 2195, in _signature_from_callable return _signature_bound_method(sig) File "/home/linux/Python/cpython/Lib/inspect.py", line 1785, in _signature_bound_method raise ValueError('invalid method signature') ValueError: invalid method signature

> Is there any reason that the second case Terry provide still will failed with ValueError? > class C: > def meth2(**kwds): pass > ip.signature(C().meth2) Yes, the reason is that `C().meth2` is an invalid method that can't be called. Try calling `C().meth2()` and you will get a TypeError. There is no bug here.

OK, we will change this example in test_calltips once calltips uses .signature (#19903).