[Python-bugs-list] [ python-Bugs-466125 ] PyLong_AsLongLong works for any integer (original) (raw)

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Mon, 01 Oct 2001 12:56:36 -0700

Bugs item #466125, was opened at 2001-09-28 09:45 You can respond by visiting: http://sourceforge.net/tracker/?func=detail&atid=105470&aid=466125&group_id=5470

Category: Python Interpreter Core Group: Feature Request Status: Closed Resolution: Fixed Priority: 5 Submitted By: Tom Epperly (tepperly) Assigned to: Tim Peters (tim_one) Summary: PyLong_AsLongLong works for any integer

Initial Comment: It would be nice if PyLong_AsLongLong worked more like PyInt_AsLong. When the value can be coerced into an integer, it should be.

The current behavior is that PyLong_AsLongLong only works (without raising an exception) on instances of a PyLongObject. I would be far better for my application, http://www.llnl.gov/casc/components/, if PyLong_AsLongLong called PyInt_AsLong in cases where the argument is not a PyLongObject. The return value of PyInt_AsLong can safely be promoted to a long long.

The end result that I would like is that an 'L' in a PyArg_ParseTuple call return any integer value (int or long) as a C long long. PyArg_ParseTuple ultimately uses PyLong_AsLongLong to handle the L format code.

It would be nice to have this behavior in past versions too (i.e. 1.5.2, 2.0 and 2.1).

Here is an example of how one might do this. This patch also changes the behavior of PyLong_AsLong to fall back on PyInt_AsLong.

$ diff -c longobject.c~ longobject.c *** longobject.c~ Wed Jan 17 07:33:18 2001 --- longobject.c Fri Sep 28 09:42:45 2001

*** 144,153 **** unsigned long x, prev; int i, sign;

! if (vv == NULL || !PyLong_Check(vv)) { PyErr_BadInternalCall(); return -1; } v = (PyLongObject *)vv; i = v->ob_size; sign = 1; --- 144,156 ---- unsigned long x, prev; int i, sign;

! if (vv == NULL) { PyErr_BadInternalCall(); return -1; }

*** 387,395 **** LONG_LONG x, prev; int i, sign;

! if (vv == NULL || !PyLong_Check(vv)) { PyErr_BadInternalCall(); return -1; }

  v = (PyLongObject *)vv;

--- 390,401 ---- LONG_LONG x, prev; int i, sign;

! if (vv == NULL) { PyErr_BadInternalCall(); return -1;

Comment By: Tim Peters (timone) Date: 2001-10-01 12:56

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Ah -- that's unlikely. There's never been a bugfix release for 1.5.2, and there won't be any more for 2.0 or 2.1 either unless someone (unexpectedly) volunteers to produce them. If someone does, what goes in would be up to them, but you're right that the bugfix-release volunteers so far have taken a strict "no new features" line.

I suppose that means you could volunteer to produce bugfix releases, though, and sneak in anything you felt like .

Comment By: Tom Epperly (tepperly) Date: 2001-09-30 11:28

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Thanks to all for making the change. It will make my Python language bindings easier and better.

When I spoke of changing it in past version, I did not mean to suggest time travel or some method of altering everyone's installations of previously released version. I was wondering if it could be included in future bug fix releases to previously released versions. However, this appears to be against your policy for bug fixes that I've gleaned from your WWW pages.

Comment By: Tim Peters (tim_one) Date: 2001-09-29 22:12

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PyLong_AsLongLong (and so also PyArg_ParseTuple 'L') now accepts longs and ints (but not types other than those and subclasses of those), for 2.2:

Doc/ext/extending.tex; new revision: 1.3 Misc/ACKS; new revision: 1.113 Misc/NEWS; new revision: 1.260 Modules/_testcapimodule.c; new revision: 1.12 Objects/longobject.c; new revision: 1.110

Comment By: Tim Peters (tim_one) Date: 2001-09-29 21:36

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Oops! What Guido did in PyLong_AsLong is back off to PyInt_AsLong but only if PyInt_Check is true. What the suggested patch does is call PyInt_AsLong in any non-NULL case where PyLong_Check is false, and that includes dubious things like converting floats to ints.

I don't think we want that, and it isn't needed for your stated goal ("'L' in a PyArg_ParseTuple call return any integer value (int or long) as a C long long").

Comment By: Tim Peters (tim_one) Date: 2001-09-29 21:20

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Hmm. The patch is against some older version of Python that doesn't bear much textual resemblance to current longobject.c (i.e., patch can't make head or tail of this).

I believe Guido already changed PyLong_AsLong(), about 2 weeks ago, to back off to PyInt_AsLong if an int object is passed in.

PyLong_AsLongLong() does not, though, and I agree it's a good idea. So I'll do that.

Tom, I hope you didn't intend your "It would be nice to have this behavior in past versions too (i.e. 1.5.2, 2.0 and 2.1)" to have more actual content than "It would be nice if people never died before they were ready to go" <0.9 wink>. But if so, we obviously can't change the behavior of code that's already been released.

Comment By: Guido van Rossum (gvanrossum) Date: 2001-09-28 10:05

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Makes sense to me. Tim, what do you think?

You can respond by visiting: http://sourceforge.net/tracker/?func=detail&atid=105470&aid=466125&group_id=5470