Re: Puzzled by list-appending behavior

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From	Terry Reedy <tjreedy@udel.edu>
Subject	Re: Puzzled by list-appending behavior
Date	Thu, 26 May 2011 14:44:52 -0400
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On 5/26/2011 3:18 AM, Algis Kabaila wrote:

> And why do you insist on calling an instance of list, "list"? Even a
> human reader will confuse which is which. What you are showing is an
> example how confusing things become when a keyword (list) is
> over-written (with list instance).

(Minor note: 'list' is not a keyword (if it were, it could not be 
over-ridden) but it is a builtin.) You are correct, it is confusing. 
Such usage will also lead to bugs if one ever tries to access the class 
as 'list' later in the program.

Here is a legitimate usage of builtins masking:

import builtins
def list(iterable):
     print('building list from {}: {}'.format(type(iterable),iterable))
     return builtins.list(iterable)

a = list((1,2,3))
b = list({1,2,3})
###
building list from <class 'tuple'>: (1, 2, 3)
building list from <class 'set'>: {1, 2, 3}

-- 
Terry Jan Reedy

Thread

Puzzled by list-appending behavior Uncle Ben <bgreen@nycap.rr.com> - 2011-05-25 21:46 -0700
  Re: Puzzled by list-appending behavior Ben Finney <ben+python@benfinney.id.au> - 2011-05-26 15:11 +1000
  Re: Puzzled by list-appending behavior Chris Rebert <clp2@rebertia.com> - 2011-05-25 22:17 -0700
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-26 17:20 +1000
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-26 17:23 +1000
  Re: Puzzled by list-appending behavior Uncle Ben <bgreen@nycap.rr.com> - 2011-05-26 00:33 -0700
  Re: Puzzled by list-appending behavior Chris Rebert <clp2@rebertia.com> - 2011-05-26 01:09 -0700
  Re: Puzzled by list-appending behavior MRAB <python@mrabarnett.plus.com> - 2011-05-26 16:58 +0100
    Re: Puzzled by list-appending behavior Tim Roberts <timr@probo.com> - 2011-05-26 23:34 -0700
      Re: Puzzled by list-appending behavior MRAB <python@mrabarnett.plus.com> - 2011-05-27 17:02 +0100
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 02:04 +1000
  Re: Puzzled by list-appending behavior John Ladasky <ladasky@my-deja.com> - 2011-05-26 11:27 -0700
    Re: Puzzled by list-appending behavior Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-27 01:59 +0000
      Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 13:24 +1000
        Re: Puzzled by list-appending behavior Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-27 03:52 +0000
          Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 14:10 +1000
          RE: Puzzled by list-appending behavior "Prasad, Ramit" <ramit.prasad@jpmchase.com> - 2011-05-27 13:58 -0400
          Re: Puzzled by list-appending behavior Ethan Furman <ethan@stoneleaf.us> - 2011-05-27 11:56 -0700
  Re: Puzzled by list-appending behavior Terry Reedy <tjreedy@udel.edu> - 2011-05-26 14:44 -0400
  RE: Puzzled by list-appending behavior "Prasad, Ramit" <ramit.prasad@jpmchase.com> - 2011-05-26 15:34 -0400
  Re: Puzzled by list-appending behavior Terry Reedy <tjreedy@udel.edu> - 2011-05-26 17:36 -0400

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