[Python-Dev] PEP 433: Choose the default value of the new cloexec parameter

[Ethan Furman]

On 01/28/2013 04:17 PM, Ralf Schmitt wrote:
> Guido van Rossum <guido at python.org> writes:
>> On Mon, Jan 28, 2013 at 1:56 PM, Ralf Schmitt <ralf at systemexit.de> wrote:
>>> Guido van Rossum <guido at python.org> writes:
>>>
>>>> Yeah, so the answer to all this is that 3rd party libraries know better
>>>> than to mess with global settings.
>>>
>>> Right. But why make it configurable at runtime then? If you're changing
>>> the value, then you're the one probably breaking third party code.
>>
>> Sigh. This is getting exasperating. There's other code that might want to
>> change this besides 3rd party library code. E.g. app configuration code.
>
> So, third party library code should know better, while at the same time
> it's fine to mess with global settings from app configuration code.
>
> That does not make sense.

Library code should not be relying on globals settings that can change. 
  Library code should be explicit in its calls so that the current value 
of a global setting is irrelevant.

~Ethan~

P.S.  Unless, of course, the library is meant to work with that global, 
and can work correctly with all of the global's valid settings.