[Python-Dev] List vs Tuple / Homogeneous vs Heterogeneous / Mutable vs Immutable

[Leandro Pereira de Lima e Silva]

That's rather vague, isn't it? "Usually contains" isn't nearly as
prescriptive as "should be used for".

A co-worker with whom I discussed the matter these days also argued that a
language shouldn't prescribe as one uses a data structure, although I do
think conventions in semantics helps maintainability.

Leandro


2014-04-18 16:59 GMT-03:00 Ezio Melotti <ezio.melotti at gmail.com>:

> Hi,
>
> On Thu, Apr 17, 2014 at 10:23 PM, Guido van Rossum <guido at python.org>
> wrote:
> > It's definitely something that should be put in some documentation,
>
> see http://bugs.python.org/issue14840 and
> https://docs.python.org/3/tutorial/datastructures.html#tuples-and-sequences
> :
> """
> Though tuples may seem similar to lists, they are often used in
> different situations and for different purposes. Tuples are immutable,
> and usually contain an heterogeneous sequence of elements that are
> accessed via unpacking (see later in this section) or indexing (or
> even by attribute in the case of namedtuples). Lists are mutable, and
> their elements are usually homogeneous and are accessed by iterating
> over the list.
> """
>
> Best Regards,
> Ezio Melotti
>
> > probably
> > at the point when people have learned enough to be designing their own
> > programs where this issue comes up -- before they're wizards but well
> after
> > they have learned the semantic differences between lists and tuples.
> >
> >
> > On Thu, Apr 17, 2014 at 11:49 AM, Brett Cannon <bcannon at gmail.com>
> wrote:
> >>
> >>
> >>
> >> On Thu Apr 17 2014 at 2:43:35 PM, Leandro Pereira de Lima e Silva
> >> <leandropls at cpti.cetuc.puc-rio.br> wrote:
> >>>
> >>> Hello there!
> >>>
> >>> I've stumbled upon this discussion on python-dev about what the choice
> >>> between using a list or a tuple is all about in 2003:
> >>> 1. https://mail.python.org/pipermail/python-dev/2003-March/033962.html
> >>> 2. https://mail.python.org/pipermail/python-dev/2003-March/034029.html
> >>>
> >>> There's a vague comment about it on python documentation but afaik
> there
> >>> the discussion hasn't made into any PEPs. Is there an understanding
> about
> >>> it?
> >>
> >>
> >> Think of tuples like a struct in C, lists like an array. That's just out
> >> of Guido's head so I don't think we have ever bothered to write it down
> >> somewhere as an important distinction of the initial design that should
> be
> >> emphasized.
> >>
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> >>
> >
> >
> >
> > --
> > --Guido van Rossum (python.org/~guido)
> >
> > _______________________________________________
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