[Tutor] the sense of brackets

[Lie Ryan]

On Sat, 22 Nov 2008 22:58:48 +0100, spir wrote:

> W W a écrit :
>  > On Sat, Nov 22, 2008 at 9:42 AM, spir <denis.spir at free.fr> wrote:
>  >
>  >> I have long thought "[]" /simply/ is a list constructor syntax. What
>  >> do you think of the following?
>  >>
>  >> t = "aze"
>  >> print t, list(t), [t]
>  >> print list(list(t)), list([t]), [list(t)], [[t]] ==>
>  >> aze ['a', 'z', 'e'] ['aze']
>  >> ['a', 'z', 'e'] ['aze'] [['a', 'z', 'e']] [['aze']]
>  >
>  > Consider the following:
>  > In [1]: list("Hello")
>  > Out [1]: ['H', 'e', 'l', 'l', 'e', 'o'] and the list docstring:
>  > list() -> new list
>  > list(sequence) -> new list initialized from sequence's items so
>  > list(list(t)) makes perfect sense: list(t) is ['a', 'z' ,'e'] and
>  > list(list(t)) simply creates a new list initialized from that list's
>  > items HTH,
>  > Wayne
> 
> Yep! What surprises me is the behaviour of [] instead. I can understand
> that list(t) != [t]
> but
> [list(t)], [[t]] --> [['a', 'z', 'e']] [['aze']] is a bit strange to me.
> 

what do you expect [] should do on that case? I think it's perfectly 
reasonable and consistent with the semantic for [] to just simply 
"enclose" whatever inside it with []s instead of converting an iterable 
to a list as list() does.