[issue20341] Argument Clinic: add "nullable ints"

Change by Brett Cannon : -- nosy: -brett.cannon ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue20341] Argument Clinic: add "nullable ints"

Change by Tal Einat : -- nosy: -taleinat ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue20341] Argument Clinic: add nullable ints

Changes by Serhiy Storchaka storch...@gmail.com: -- components: +Argument Clinic ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___ ___

[issue20341] Argument Clinic: add nullable ints

Changes by Josh Rosenberg shadowranger+pyt...@gmail.com: -- nosy: +josh.r ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___ ___

[issue20341] Argument Clinic: add nullable ints

Martin v. Löwis added the comment: If this feature is contentious, then a PEP is need to decide on it. As it turns out, PEP 436 already discusses the nullable feature. But, as it also turns out, PEP 436 hasn't been accepted yet (at least I could not find any records on that having happened,

[issue20341] Argument Clinic: add nullable ints

Raymond Hettinger added the comment: FWIW, I agree with Antoine that Nullable Int is a misnomer. Also, I don't buy into this mission to change signatures for optional ints into int-or-none. In particular, itertools.repeat() is fine as-is. Optional int APIs have been around for a long time,

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: FWIW, Martin agreed with me at EuroPython that nullable int is the proper name. So does Wikipedia: http://en.wikipedia.org/wiki/Nullable_type As for repeat_new: like I said, I don't intend to check in this change when checking in nullable ints. (I

[issue20341] Argument Clinic: add nullable ints

Raymond Hettinger added the comment: Larry, ISTM that you are bulldozing your way through something that isn't an actual problem to be solved. I can see why you'd think this was a waste of time. I don't think it is just a waste of time; I think it is a bad idea. You have a very strong

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Here's a fresh patch. After discussing with Martin at EuroPython, I moved the implementation into Python/getargs.c, and the prototypes into modsupport.h. I'm still using the example of repeat.new to show what it looks like and how it works. However I don't

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Whoops, here's the patch. -- Added file: http://bugs.python.org/file36165/larry.nullable.ints.4.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Yes, that is a different name that seems to mean much the same thing. and which is much more understandable by a Python developer. Thanks for your opinion. Changing error to an char and moving it to the end would save exactly zero bytes, because the

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: I insist that nullable is a very bad name. It also suggests that somehow we'll get a NULL pointer (in C) when the parameter is absent or None, which is not the case. -- ___ Python tracker rep...@bugs.python.org

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: I think it's a fine name, otherwise I would not have chosen it in the first place. Your high-spirited bikeshedding has been noted and not acted upon. I have no plans to change the name. Please drop it. -- ___

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: The only place where nullable appears in the doc tree is... clinic.rst (in reference to places where a C pointer can be NULL, which *is* a reasonable use of the term). There's another problem in the patch: if you define nullable_int_t and nullable_Py_ssize_t

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: How many existing occurrences of or_none did you find in the CPython tree? Perhaps we can turn our attention to other languages like SQL and C# and borrow their term for value that is allowed to be of a specific type (or types) as well as the null value.

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: How many existing occurrences of or_none did you find in the CPython tree? If I split that into the individual words or and None, quite a lot. Looking for or None turns quite a bunch of matches too. or_none simply applies the PEP 8 convention for variable

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Drop. It. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___ ___ Python-bugs-list mailing list

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: Drop. It. Seriously? Why exactly did you ask for comments if your only response is to be snarky and dismissive? This is not your toy project. It is perfectly legitimate for us to question API and naming decisions. --

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: I don't think it's fair to call my responses snarky. On the other hand, your suggestion that I view Argument Clinic as my toy project is obviously meant as an insult. It is fair to call my responses dismissive, because I find nothing compelling about your

[issue20341] Argument Clinic: add nullable ints

Changes by Antoine Pitrou pit...@free.fr: -- nosy: -pitrou ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___ ___ Python-bugs-list mailing

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: I would color your final sentence slightly. Yes, there are plenty of legitimate discussions about API semantics and nomenclature. But there are infinitely many pointless and time-wasting discussions. Therefore not every question about API and naming

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: The bug you saw was an easy fix; the converter function needs to return 1 (success) from the == Py_None branch. And yes, more unit tests would be good, fixing the documentation would be good too. I did say the patch was nowhere near ready. I will assume

[issue20341] Argument Clinic: add nullable ints

Tal Einat added the comment: You look very handsome today Larry :) Regardless, I do think this is a good idea. I've converted several functions that have -1 as a default value for ints where they ideally should have None. Having None as the default will be much clearer and less error prone

[issue20341] Argument Clinic: add nullable ints

Tal Einat added the comment: My only comment from reviewing the patch is that you seem to have used NULLABLE_PY_SSIZE_T_INITIALIZE by accident one time in int_converter (in clinic.py). Other than that, as you already know, make sure to return 1 in both converters in the if (arg == Py_None)

[issue20341] Argument Clinic: add nullable ints

Serhiy Storchaka added the comment: I don't remember who specifically needed the nullable ints, so I just added a bunch of Derby contestants. There are no much need in nullable ints, if they are needed, different use cases require different semantic. I don't think we can now write general

[issue20341] Argument Clinic: add nullable ints

Serhiy Storchaka added the comment: And thank you for the fix for the __init__ methods. Could you please commit it? The I'll update patches for bz2 and lzma modules. Looks as Vajrasky Kok has encountered with yet one bug in generated __init__ wrapper(issue20185). --

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Then you disagree with Guido, who says that optional integer arguments without a viable publishable default value should accept None to mean use the default value: https://mail.python.org/pipermail/python-dev/2014-January/131673.html

[issue20341] Argument Clinic: add nullable ints

Serhiy Storchaka added the comment: I thought it was too late for 3.4, and the conversion should not change the behavior (we can change the behavior later in 3.5). -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: I guess we should ask Guido for clarification. But I got the impression that we could *gently* tweak the signatures of functions if they were not representable in Python syntax. He thought that giving the parameter of _sha1.sha1() a default value of b'' was

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Actually, the documented behavior of itertools.repeat() is that the times argument takes a default of None. Equivalent to: def repeat(object, times=None): ... http://docs.python.org/3/library/itertools.html#itertools.repeat --

[issue20341] Argument Clinic: add nullable ints

Changes by Jeremy Kloth jeremy.kloth+python-trac...@gmail.com: -- nosy: +jkloth ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341 ___ ___

[issue20341] Argument Clinic: add nullable ints

Tal Einat added the comment: Found two bugs in the draft patch in Objects/longobject.c: 1) In _PyLong_NullableIntConverter, there is no index variable, so the Py_DECREF and Py_XDECREF need to be removed from the end of the function. 2) In _PyLong_NullablePy_ssize_tConverter, the index

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: Some things: - the concept of a nullable thing in Python doesn't exist; why not optional? - why is there a error field in the new structs? - the fact that the structs are defined in longobject.h looks bonkers - boolean fields can be char instead of int (and

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: - the concept of a nullable thing in Python doesn't exist; why not optional? That's not what it means. Python parameters are optional if they have a default value. These parameters are nullable, in the sense that they can be either of a specific type or None.

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: That's not what it means. Python parameters are optional if they have a default value. These parameters are nullable, in the sense that they can be either of a specific type or None. (But Noneable seemed like a bad name). They are not necessarily

[issue20341] Argument Clinic: add nullable ints

Tal Einat added the comment: Another bug in the patch: In int_converter.__init__ in clinic.py, the patch adds: if not isinstance(self.default, int): fail(Illegal default value for int_converter) This fails if no default is specified, e.g. for positional only argument. The condition

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: int(or_none=True) ? Yes, that is a different name that seems to mean much the same thing. Hmm, do we have a getargs.h ? No. Would it help if I attached the output of ls Include to this issue? - boolean fields can be char instead of int (and moved at

[issue20341] Argument Clinic: add nullable ints

Antoine Pitrou added the comment: int(or_none=True) ? Yes, that is a different name that seems to mean much the same thing. and which is much more understandable by a Python developer. Changing error to an char and moving it to the end would save exactly zero bytes, because the compiler

[issue20341] Argument Clinic: add nullable ints

Tal Einat added the comment: The new patch still uses NULLABLE_PY_SSIZE_T_INITIALIZE instead of NULLABLE_INT_T_INITIALIZE in one place in int_converter.converter_init. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: Fix attached. Might as well. -- Added file: http://bugs.python.org/file33639/larry.nullable.ints.draft.3 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue20341

[issue20341] Argument Clinic: add nullable ints

New submission from Larry Hastings: Attached is a *preliminary* patch for Argument Clinic that adds nullable ints. If you use the converter int(nullable=True), then: * The type you get back is not int but nullable_int_t, a structure containing three fields: error, is_null, and i. error is

[issue20341] Argument Clinic: add nullable ints

Larry Hastings added the comment: I should have mentioned--a sample using nullable ints is in itertoolsmodule.c. longobject.{ch} changed to add the converters, and obviously clinic.py changed to add support for the converters. -- ___ Python

[issue20341] Argument Clinic: add nullable ints

Vajrasky Kok added the comment: itertools.repeat.__doc__ 'repeat(object, times=None)\nReturns an iterator which returns the object the specified number of times.\n\nIf times is None, returns the object endlessly.' itertools.repeat('a', times=None) Traceback (most recent call last): File