Re: Bitten by my C/Java experience

From	random832@fastmail.us
Subject	Re: Bitten by my C/Java experience
Date	2015-05-04 17:16 -0400
References	<87r3qwid3u.fsf@Equus.decebal.nl> <mailman.97.1430761463.12865.python-list@python.org> <mi8mf6$k1$1@flame.srcf.net>
Newsgroups	comp.lang.python
Message-ID	<mailman.106.1430774166.12865.python-list@python.org> (permalink)

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On Mon, May 4, 2015, at 16:57, Andrew Cooper wrote:
> * {} is an empty set(), not dict().

You've got it backwards.

> Particularly subtle when combined with **kwargs

The function in your example below _always_ returns a set, and kwargs is
always a dict. There's no subtlety outside of the repr output. The fact
that the empty set (as a result of empty kwargs) repr's as set() is a
consequence of the fact that {} is a dict.

> 
> $ python3
> Python 3.4.0 (default, Apr 11 2014, 13:05:11)
> [GCC 4.8.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> def foo(**kwargs):
> ...   return { (k, kwargs[k]) for k in kwargs }
> ...
> >>> foo()
> set()
> >>> foo(a=1)
> {('a', 1)}
> >>>
> 
> ~Andrew
> -- 
> https://mail.python.org/mailman/listinfo/python-list

-- 
Random832

Thread

Bitten by my C/Java experience Cecil Westerhof <Cecil@decebal.nl> - 2015-05-04 17:20 +0200
  Re: Bitten by my C/Java experience Tobiah <toby@tobiah.org> - 2015-05-04 10:18 -0700
  Re: Bitten by my C/Java experience Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2015-05-04 19:32 +0200
    Re: Bitten by my C/Java experience Chris Angelico <rosuav@gmail.com> - 2015-05-05 03:40 +1000
      Re: Bitten by my C/Java experience albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-08 10:47 +0000
        Re: Bitten by my C/Java experience Chris Angelico <rosuav@gmail.com> - 2015-05-08 21:32 +1000
  Re: Bitten by my C/Java experience Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-04 11:43 -0600
    Re: Bitten by my C/Java experience Andrew Cooper <amc96@cam.ac.uk> - 2015-05-04 21:57 +0100
      Re: Bitten by my C/Java experience random832@fastmail.us - 2015-05-04 17:16 -0400
      Re: Bitten by my C/Java experience Tim Chase <python.list@tim.thechases.com> - 2015-05-04 16:26 -0500
  Re: Bitten by my C/Java experience Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-04 18:59 +0100
  Re: Bitten by my C/Java experience Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-04 13:39 -0600
    Re: Bitten by my C/Java experience Cecil Westerhof <Cecil@decebal.nl> - 2015-05-04 22:28 +0200
      Re: Bitten by my C/Java experience Dave Angel <davea@davea.name> - 2015-05-04 19:17 -0400
  Re: Bitten by my C/Java experience Terry Reedy <tjreedy@udel.edu> - 2015-05-04 16:06 -0400
  Re: Bitten by my C/Java experience BartC <bc@freeuk.com> - 2015-05-04 23:02 +0100
    Re: Bitten by my C/Java experience Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-05 18:19 +1000
      Re: Bitten by my C/Java experience BartC <bc@freeuk.com> - 2015-05-05 14:20 +0100
        Re: Bitten by my C/Java experience Rustom Mody <rustompmody@gmail.com> - 2015-05-05 09:24 -0700
          Re: Bitten by my C/Java experience Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-05-06 14:38 +0200
            Re: Bitten by my C/Java experience Rustom Mody <rustompmody@gmail.com> - 2015-05-06 06:03 -0700
        Re: Bitten by my C/Java experience Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-06 23:19 +1200
          Re: Bitten by my C/Java experience BartC <bc@freeuk.com> - 2015-05-06 13:40 +0100
            Re: Bitten by my C/Java experience Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-07 02:03 +1000
              Re: Bitten by my C/Java experience Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-06 21:13 +0100
      Re: Bitten by my C/Java experience Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-06 23:15 +1200
    Re: Bitten by my C/Java experience random832@fastmail.us - 2015-05-06 09:11 -0400
    Re: Bitten by my C/Java experience Chris Angelico <rosuav@gmail.com> - 2015-05-06 23:16 +1000

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