[Python-3000] Set literal

[Steven Bethard]

On Jan 25, 2008 1:31 PM, J. Cliff Dyer <jcd at sdf.lonestar.org> wrote:
>
>  I'm a -0.9 on this one.  I really like that Python is powerful, but also a
> great pedagogical language.
>
>  I don't like that whereas before you could teach someone {} creates a dict,
> but now you have to say {} creates a dict, if there are colons inside, or
> it's empty, but otherwise creates a frozenset.  I also don't like that it
> will be easy (especially coming from Certain Other Languages) to make the
> following error:
>
>  my_dict = {
>      'a', 'b',
>      'c', 'd',
>      'e', 'f'
>  }
>
>  Moreover, I don't like that once you've done that, you'll be able to do
>
>  if 'c' in my_dict:
>      ...
>
>  and have it evaluate as true even though you aren't dealing with a dict.

You're a little late for this discussion.  Python 3.0 already has this
behavior::

    Python 3.0a2+ (py3k:60260, Jan 25 2008, 13:40:11)
    [MSC v.1500 32 bit (Intel)] on win32
    Type "help", "copyright", "credits" or "license" for more information.
    >>> my_dict = {
    ...     'a', 'b',
    ...     'c', 'd',
    ...     'e', 'f',
    ... }
    >>> 'c' in my_dict
    True

This discussion is about whether the set literal should be a set() or
a frozenset().

STeVe
-- 
I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a
tiny blip on the distant coast of sanity.
        --- Bucky Katt, Get Fuzzy