[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Roundup Robot added the comment: New changeset e4617650f006 by Larry Hastings in branch 'default': Issue #14705: Added support for the new 'p' format unit to skipitem(). http://hg.python.org/cpython/rev/e4617650f006 -- ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Changes by Larry Hastings : -- status: open -> closed ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://ma

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Roundup Robot added the comment: New changeset 05274ab06182 by Larry Hastings in branch 'default': Update Misc/NEWS for issues #14127 and #14705. (And, technically, #10148.) http://hg.python.org/cpython/rev/05274ab06182 -- ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Changes by Larry Hastings : -- resolution: -> fixed stage: patch review -> committed/rejected ___ Python tracker ___ ___ Python-bugs-

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Roundup Robot added the comment: New changeset 709850f1ec67 by Larry Hastings in branch 'default': Update Misc/NEWS for issues #14127 and #14705. (And, technically, #10148.) http://hg.python.org/cpython/rev/709850f1ec67 -- ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: > I would have expected a bool parse code to insist on a boolean, I originally had a second form ('P') that insisted on a boolean as you suggest. But nobody could come up with a use case. So I removed it in the final patch. Please see this issue for the di

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Raymond Hettinger added the comment: I would have expected a bool parse code to insist on a boolean, so that: int x; PyArg_ParseTupleAndKeywords(args, kwds, "p:func", &x); would behave the same as: PyObject *o; int x; PyArg_ParseTupleAndKeywords(args, kwds, "O!:func", &Py

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: Eh, it was ready, why wait? Thanks everybody for your feedback! -- ___ Python tracker ___ ___ Pyth

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Roundup Robot added the comment: New changeset bc6d28e726d8 by Larry Hastings in branch 'default': Issue #14705: Add 'p' format character to PyArg_ParseTuple* for bool support. http://hg.python.org/cpython/rev/bc6d28e726d8 -- nosy: +python-dev ___ Py

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Mark Dickinson added the comment: Latest patch looks good to me. -- ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscr

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: > I hope I haven't made a lot of mistakes in the previous sentence. It depends, do you consider three "a lot"? ;-) Attached is a new patch removing 'P'. (The regrtest is still running but I don't expect any failures.) I'm guessing I won't get any further

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: > Do you still think 'P' is better than 'p'? No. I hope I haven't made a lot of mistakes in the previous sentence. -- ___ Python tracker __

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: Serhiy, I'm having a little trouble with your English. (But I'm sure your English is far better than my... uh, anything besides English.) So let me ask a question with a clear yes/no answer: Do you still think 'P' is better than 'p'? -- __

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: > That's not a reason to use 'P'. Why you should use 'P' in the first place? I just guided by the principle "Explicit is better than implicit". Statements 'if' and 'while' I consider explicit and expect cast to bool. Implicit cast to bool in the transfer of

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Mark Dickinson added the comment: > I considered briefly trying to make 'P' handle subclasses of bool. Not an issue: bool can't be subclassed. :-) Python 3.2.3 (default, Apr 13 2012, 00:15:25) [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin Type "help", "copyright", "credits" or "licen

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Mark Dickinson added the comment: > Having meditated on it, I think either I should either just call > PyErr_Occured, check for explicit failure (val < 0), or explicit success > (val >= 0). I've opted for the last of those. Yes, I think that works; it avoids a relatively expensive PyErr_Occurr

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Georg Brandl added the comment: Indeed, "because the code is written" is not a good argument if even you yourself are -0. -- nosy: +georg.brandl ___ Python tracker ___

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Benjamin Peterson added the comment: Since no one has produced a good example needing "P", I say drop it. At any rate, it can be almost trivially imitated with "O!". -- nosy: +benjamin.peterson ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: Attached is rev 3 of my patch, incorporating mainly backing out of dumb ideas. Thanks for the feedback, Serhiy and Mark! > My name is Serhiy. :) My genuine apologies! In my defense it was rather late. > 'P' has the advantage that you can safely backward-

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Mark Dickinson added the comment: In this line in the patch (Python/getargs.c): +if (val == -1 || PyErr_Occurred()) { Isn't that call to PyErr_Occurred() redundant? -- ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Eric V. Smith added the comment: If bool_new() is going to use 'p', then my suggestion shouldn't be the only test of 'p'. -- ___ Python tracker ___

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: > Since the salient point is that 'p' returns the same value as bool(), right? Yes, and bool_new() is a candidate number one for using new feature. -- ___ Python tracker __

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: > Serily: why would you unhesitatingly prefer 'P' to 'p'? My name is Serhiy. :) 'P' has the advantage that you can safely backward-compatibly remove the restriction by replacing 'P' on 'p'. :) > I also found some funny in-between cases. This is historical

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Eric V. Smith added the comment: Now that I think about this some more, I think I'd structure the 'p' tests as: for expr in [False, None, True, 1, 0]: # add the rest self.assertEqual(bool(expr), getargs_p(expr)) Since the salient point is that 'p' returns the same value as bool(), right?

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: Added test forcing a failure for 'p' (and 'P'). This made me have to handle errors a little differently, so it was definitely good to test it. Thanks for the suggestion, Martin! Also changed wording in documentation ever-so-slightly. -- Added file:

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Martin v. Löwis added the comment: >> I think there should be a test case also where PyObject_IsTrue gives an >> exception (which I think can happen if __bool__ raises an exception). > > I'd be happy to add such a test, but I don't know of any types like > that. Can anyone suggest one? class

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: > I think there should be a test case also where PyObject_IsTrue gives an > exception (which I think can happen if __bool__ raises an exception). I'd be happy to add such a test, but I don't know of any types like that. Can anyone suggest one? -- __

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Martin v. Löwis added the comment: I think there should be a test case also where PyObject_IsTrue gives an exception (which I think can happen if __bool__ raises an exception). -- nosy: +loewis ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: I looked through the Python sources and couldn't find any instances of a function or method with an argument that only allowed you to pass in either True or False. Serily already said he would use 'P' over 'p', although I too am unconvinced that's a good id

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Mark Dickinson added the comment: I also think that 'P' looks too strict to be really useful. I can't think of too many cases where I'd really want to insist on a boolean argument (and reject values of 0 or 1). Maybe implement just 'p' for now and consider 'P' later? -- nosy: +mark.

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Eric V. Smith added the comment: The patch looks good to me. Are there any places in the current code base that would use "P"? "p" seems the more useful case. Are you planning on changing existing code to use P or p, or just use it going forward? -- nosy: +eric.smith __

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: Patch looks good to me. I however prefer to use 'P'. -- ___ Python tracker ___ ___ Python-bugs-l

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: My first patch. Adds 'p' and 'P', along with documentation and unit tests. -- keywords: +patch stage: -> patch review Added file: http://bugs.python.org/file25441/larry.parse.tuple.p.and.P.1.diff ___ Python tracker

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Larry Hastings added the comment: > For this purpose it is appropriate to use a special converter > (with 'O&'). The converter works--but, then, a similar converter would also work for double, and float, and long long and many others. If long long is special enough to merit explicit support in

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

Serhiy Storchaka added the comment: Yes, I too have encountered this in the process of working on issue 14626. For this purpose it is appropriate to use a special converter (with 'O&'). I suppose it must be a strict сonverter; there is no point in specifying followlinks=[1, 2, 3]. If it is so

[issue14705] Add 'bool' format character to PyArg_ParseTuple*

New submission from Larry Hastings : Currently functions that parse their arguments with the PyArg_ParseTuple family which want to take a boolean-ish parameter face two choices: * take an "int", then test whether or not the int is 0, or * take an "object", then call PyObject_IsTrue themselve