[Python-Dev] sys.implementation (original) (raw)

Brett Cannon brett at python.org
Wed May 9 16:44:59 CEST 2012

On Wed, May 9, 2012 at 5:57 AM, "Martin v. Löwis" <martin at v.loewis.de>wrote:

On 27.04.2012 09:34, Eric Snow wrote:

On Thu, Apr 26, 2012 at 8:31 AM, Barry Warsaw<barry at python.org> wrote:

It's somewhat of a corner case, but I think a PEP couldn't hurt. The rationale section would be useful, at least.

http://mail.python.org/pipermail/python-ideas/2012- April/014954.html<http://mail.python.org/pipermail/python-ideas/2012-April/014954.html> Interesting proposal. I have a number of comments: - namespace vs. dictionary. Barry was using it in the form sys.implementation.version. I think this is how it should work, yet the PEP says that sys.implementation is a dictionary, which means that you would need to write sys.implementation['version'] I think the PEP should be silent on the type of sys.implementation, in particular, it should not mandate that it be a module (else "from sys.implementation import url" ought to work) [Update: it seems this is already reflected in the PEP. I wonder where the requirement for "a new type" comes from. I think making it a module should be conforming, even though probably discouraged for cpython, as it would make people think that they can rely on it being a module.

That stems from people arguing over whether sys.implementation should be a dict or a tuple, and people going "it shouldn't be a sequence since it lacks a proper order", but then others saying "it shouldn't be a dict because it isn't meant to be mutated" (or something since I argued for the dict). So Eric (I suspect) went with what made sense to him.

I wish there was a builtin class

class record: pass which can be used to create objects which have only attributes and no methods.

I have heard this request now a bazillion times over the years. Why don't we have such an empty class sitting somewhere in the stdlib with a constructor classmethod to simply return new instances (and if you want to get really fancy, optional keyword arguments to update the instance with the keys/values passed in)? Is it simply because it's just two lines of Python that everyone has replicated at some point?

-Brett

Making it a type should also work:

class implementation: name = "cpython" version = (3,3,0) in which case it would an instance of an existing type, namely, "type"] - under-specified attributes: "run-time environment" doesn't mean much to me - my first guess is that it is the set of environment variables, i.e. a dictionary identical to os.environ. I assume you mean something different ... gctype is supposedly a string, but I cannot guess what possible values it may have. I also wonder why it's relevant. Regards, Martin _______** Python-Dev mailing list Python-Dev at python.org http://mail.python.org/**mailman/listinfo/python-dev<http://mail.python.org/mailman/listinfo/python-dev> Unsubscribe: http://mail.python.org/mailman/options/python-dev/ brett%40python.org<http://mail.python.org/mailman/options/python-dev/brett%40python.org> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20120509/3e5fe551/attachment.html>

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