[Python-Dev] pyc files, constant folding and borderline portability issues (original) (raw)

Cesare Di Mauro cesare.dimauro at a-tono.com
Tue Apr 7 18:46:29 CEST 2009

On Tue, Apr 7, 2009 06:25PM, Guido van Rossum wrote:

Well I'm sorry Cesare but this is unacceptable. As Skip points out there is plenty of code that relies on this.

Guido, as I already said, in the final code the normal Python behaviour will be kept, and the stricter one will be enabled solely due to a flag set by the user.

Also, consider what "problem" you are trying to solve here. What is the benefit to the user of moving this error to compile time? I cannot see any.

--Guido

In my experience it's better to discover a bug at compile time rather than at running time.

Cesare

On Tue, Apr 7, 2009 at 8:19 AM, Cesare Di Mauro <cesare.dimauro at a-tono.com> wrote:

In data 07 aprile 2009 alle ore 17:19:25, <skip at pobox.com> ha scritto:

Cesare> The only difference at this time is regards invalid operations, Cesare> which will raise exceptions at compile time, not at running Cesare> time. Cesare> So if you write: Cesare> a = 1 / 0 Cesare> an exception will be raised at compile time. I think I have to call bzzzzt here.  This is a common technique used during debugging.  Insert a 1/0 to force an exception (possibly causing the running program to drop into pdb).  I think you have to leave that in. Skip Many tests rely on this, and I have changed them from something like: try: 1 / 0 except:  .... to try:  a = 1; a / 0 except:  .... But I know that it's a major source of incompatibilities, and in the final code I'll enabled it only if user demanded it (through a flag). Cesare

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-- --Guido van Rossum (home page: http://www.python.org/~guido/)

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