[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Serhiy Storchaka added the comment: I meant that I looked up the code of functools.update_wrapper() and did not see that it sets the __defaults__ attribute. In your example in msg392643 you use functools.update_wrapper() incorrectly. The first argument is wrapper, and the second argument is

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: rejecting. code trying to make direct use of __defaults__ is likely better off using inspect.signature(). there might be an issue with inspect in some cases (https://bugs.python.org/issue41232) but I do not believe that is true for lru_cache wrapped thin

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: Oh, I didn't realize mutating those would actually change the code runtime behavior. But it makes sense, those are needed before the code object is entered. Yeah that is different, and suggests making this the default is not actually desired. (this issu

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Raymond Hettinger added the comment: I don't really like it. Carrying forward these attributes isn't the norm for wrapping functions. The __defaults__ argument is normally only used where it has an effect rather than in a wrapper where it doesn't. Given that it is mutable, it invites a

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Change by Gregory P. Smith : -- type: behavior -> enhancement versions: -Python 3.10, Python 3.9 ___ Python tracker ___ ___ Python-

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: https://bugs.python.org/issue41232 covers the more general case of suggesting changing update_wrapper's behavior. That would alleviate the need to fix the pure python implementation within my own PR. -- ___ Pyt

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Change by Raymond Hettinger : -- nosy: +ncoghlan ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: An inner function can't know if somebody else might want to inspect it. This is a decorator that does not change anything about the argument signature of the wrapped function, carrying over the reference to meta-information about that by default seems to

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: __defaults__ and __kwdefaults__ get used for code introspection. Just as __annotations__ does. __annotations__ is already available on the lru_cache wrapped function. All of those seem to go together from a runtime inspection point of view. --

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Change by Gregory P. Smith : -- keywords: +patch pull_requests: +24487 stage: needs patch -> patch review pull_request: https://github.com/python/cpython/pull/25800 ___ Python tracker

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Raymond Hettinger added the comment: I don't think this should be done. We want the lru_cache to be a pass-through. Applying defaults or keyword-only/positional-only restrictions is the responsibility of the inner function. FWIW, here are the fields that Nick selected to be included in

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: the pure python functools.lru_cache doesn't get this right either. here's a desirable testcase for this bug: ``` def test_lru_defaults_bug44003(self): @self.module.lru_cache(maxsize=None) def func(arg='ARG', *, kw='KW'): ret

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Gregory P. Smith added the comment: That was anecdotal evidence: ``` Python 3.9.1 (v3.9.1:1e5d33e9b9, Dec 7 2020, 12:10:52) [Clang 6.0 (clang-600.0.57)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> def func(arg=1, *, kwarg=2): pass ... >>> import func

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

Serhiy Storchaka added the comment: Where does functools.update_wrapper() set __defaults__? -- ___ Python tracker ___ ___ Python-bu

[issue44003] functools.lru_cache omits __defaults__ attribute from wrapped function

New submission from Gregory P. Smith : When the C implementation of functools.lru_cache was added in bpo/issue14373, it appears to have omitted setting `.__defaults__` on its wrapped function. ``` Python 3.10.0a7+ (heads/master-dirty:823fbf4e0e, May 1 2021, 11:10:30) [Clang 12.0.0 (clang-12