Re: Default scope of variables

References	<51d4eb9c$0$29999$c3e8da3$5496439d@news.astraweb.com> <CAPTjJmp2dpbRxbWct-oBuhM9b1WynjP-w0WVN=C1vEk0oJMBMA@mail.gmail.com> <CAN1F8qU=SPw=1nR9G_LR0BKfpr8NSNcL1iepiHo0XzXoAMYA4Q@mail.gmail.com> <CAPTjJmr9K0eW6Giwifb1iBmavCoZEuY4mTQ7xBDWi1Ko=Qex1w@mail.gmail.com>
From	Joshua Landau <joshua.landau.ws@gmail.com>
Date	2013-07-04 06:09 +0100
Subject	Re: Default scope of variables
Newsgroups	comp.lang.python
Message-ID	<mailman.4205.1372914587.3114.python-list@python.org> (permalink)

Show all headers | View raw

On 4 July 2013 05:36, Chris Angelico <rosuav@gmail.com> wrote:
> On Thu, Jul 4, 2013 at 2:30 PM, Joshua Landau
> <joshua.landau.ws@gmail.com> wrote:
>> That said, I'm not too convinced. Personally, the proper way to do
>> what you are talking about is creating a new closure. Like:
>>
>> for i in range(100):
>>     with new_scope():
>>         for i in range(100):
>>             func(i)
>>     func(i) # Using i from original loop
>>
>> But it's not like Python'll ever support that.
>>
>
> def foo():
>   for i in range(3):
>     print("outer",i)
>     def inner():
>       for i in range(4):
>         print("inner",i)
>     inner()
>     print("outer",i)
>
> That works, but you then have to declare all your nonlocals, and it
> hardly reads well.

Unfortunately that's what people, I included, end up doing. Stuff like:

def paranoia(...):
    def safe_recursive(...):
        safe_recursive(...)
    return safe_recursive
safe_recursive = paranoia()

is blimmin ugly. Then you're only really left with

class safe_recursive:
    def __call__(self, ...):
        self(...)

which only solves it for recursive functions.

I guess this means I actually agree with your sentiment, just not the specifics.

Thread

Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-04 03:27 +0000
  Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-04 14:07 +1000
    Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-04 05:32 +0000
      Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-04 15:47 +1000
        Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-04 16:38 +0000
          Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-05 02:58 +1000
          Re: Default scope of variables Wayne Werner <wayne@waynewerner.com> - 2013-07-07 08:13 -0500
          Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-07 23:43 +1000
            Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-07 16:03 +0000
              Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-08 10:46 +1000
            Re: Default scope of variables alex23 <wuwei23@gmail.com> - 2013-07-09 14:52 +1000
              Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-09 15:07 +1000
                Re: Default scope of variables alex23 <wuwei23@gmail.com> - 2013-07-09 16:08 +1000
                Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-09 16:13 +1000
                Re: Default scope of variables "Frank Millman" <frank@chagford.com> - 2013-07-09 09:35 +0200
                Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-09 17:45 +1000
                Re: Default scope of variables Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-09 01:56 -0600
                Re: Default scope of variables "Frank Millman" <frank@chagford.com> - 2013-07-09 10:22 +0200
                Re: Default scope of variables "Frank Millman" <frank@chagford.com> - 2013-07-09 10:38 +0200
                Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-09 09:07 -0700
                Re: Default scope of variables Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-09 10:44 -0600
                Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-09 10:23 -0700
                Re: Default scope of variables Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-09 12:41 -0600
                Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-09 12:19 -0700
                Re: Default scope of variables "Frank Millman" <frank@chagford.com> - 2013-07-10 07:54 +0200
                Re: Default scope of variables Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-10 09:42 -0600
                Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-10 08:29 -0700
                Re: Default scope of variables "Frank Millman" <frank@chagford.com> - 2013-07-11 07:52 +0200
          Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-07 09:52 -0700
          Re: Default scope of variables Ethan Furman <ethan@stoneleaf.us> - 2013-07-07 11:59 -0700
          Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-08 10:48 +1000
            Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-08 02:23 +0000
              Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-08 13:11 +1000
                Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-08 05:00 +0000
                Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-08 15:14 +1000
      Re: Default scope of variables Peter Otten <__peter__@web.de> - 2013-07-04 08:48 +0200
      Re: Default scope of variables Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-04 01:12 -0600
      Re: Default scope of variables Dave Angel <davea@davea.name> - 2013-07-04 03:06 -0400
        Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-04 15:52 +0000
        Re: Default scope of variables Rotwang <sg552@hotmail.co.uk> - 2013-07-04 17:54 +0100
          Re: Default scope of variables Peter Otten <__peter__@web.de> - 2013-07-04 20:36 +0200
          Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-05 01:04 +0100
          Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-05 01:24 +0000
            Re: Default scope of variables Dave Angel <davea@davea.name> - 2013-07-04 22:03 -0400
            Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-05 03:29 +0100
            Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-05 03:27 +0100
            Re: Default scope of variables Rotwang <sg552@hotmail.co.uk> - 2013-07-05 07:28 +0100
        Re: Default scope of variables Neil Cerutti <neilc@norwich.edu> - 2013-07-05 13:24 +0000
          Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-05 23:43 +1000
            Re: Default scope of variables Neil Cerutti <neilc@norwich.edu> - 2013-07-05 15:36 +0000
          Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-07 16:08 +0000
            Re: Default scope of variables Neil Cerutti <neilc@norwich.edu> - 2013-07-08 11:54 +0000
              Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-08 14:14 +0100
      Re: Default scope of variables Lele Gaifax <lele@metapensiero.it> - 2013-07-04 14:43 +0200
      Re: Default scope of variables Wayne Werner <wayne@waynewerner.com> - 2013-07-04 10:45 -0500
  Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-04 05:30 +0100
    Re: Default scope of variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-04 05:45 +0000
  Re: Default scope of variables Chris Angelico <rosuav@gmail.com> - 2013-07-04 14:36 +1000
  Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-04 06:09 +0100
  Re: Default scope of variables Joshua Landau <joshua.landau.ws@gmail.com> - 2013-07-08 17:58 +0100

csiph-web