Solutions for LC_NUMERIC, was Re: [Python-Dev] Re: Be Honest about LC_NUMERIC [REPOST] (original) (raw)

Gustavo J A M Carneiro gjc at inescporto.pt
Tue Sep 16 18:04:42 EDT 2003

A Qua, 2003-09-03 às 22:32, Martin v. Löwis escreveu:

Christian Reis <kiko at async.com.br> writes:

> "On glibc-based systems, Python is safe from runtime changes in the > LCNUMERIC locale category. On other platforms, changing LCNUMERIC > at runtime may cause float conversion routines to fail. This may > impact the Python interpreter internally." I could accept such a limitation. However, I maintain that the aspects must be fully understood, and I agree with Guido that they must be documented in the documentation proper (i.e. as comments in the source code, or the user documentation). So I suggest that you proceed with the PEP and the implementation as-is. The PEP would need to be enhanced to summarize this discussion (perhaps listing the alternatives that you just mentioned); the patch would need to be enhanced to be more simple, readable, and in the style of the rest of the Python source code, and would need to include documentation changes and test cases (although some test cases probably already exist).

I have updated the patch[1], with James Henstridge's cleaned up code (and some more cleanup). I am aware it still needs more comments and test cases, but interested parties might want to start looking at it.

Please note that, after some discussion, we have concluded it is better not to use glibc locale extensions to implement thread-safe float conversion. The main reasons are: (1) simplicity (no ifdefs); (2) consistency between glibc and non-glibc platforms. We should accept the fact python programs should not be allowed change locale after creating threads, period. Perhaps python itself should raise an exception if this is ever attempted. This is subject to discussion, of course! ;)

Regards.

[1] http://sourceforge.net/tracker/download.php?group_id=5470&atid=305470&file_id=61688&aid=774665

-- Gustavo J. A. M. Carneiro <gjc at inescporto.pt> <gustavo at users.sourceforge.net>

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