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

[Jeff Allen]

The "think of tuples like a struct in C" explanation immediately 
reminded me that ...

On 16/04/2014 21:42, Taavi Burns wrote (in his excellent notes from the 
language summit):
>   The demographics have changed. How do
> we change the docs and ecosystem to avoid the assumption that Python
> programmers already know how to program in C?
Good question. My version was going to be that if you are dealing with 
tuples of mixed data like (name, age, shoesize), inserting something or 
sorting, in the way a list can, would confuse your code. A list, you 
almost always iterate over, to do the same thing with each member, and 
that only works if they are the same type of thing.

Then I realised David Beazley had explained this (but better), starting 
in the Tuples section of his "Python Essential Reference". With 
permission, this could perhaps be adopted wherever it best fits in the 
documentation.

Jeff Allen

On 17/04/2014 20:49, Leandro Pereira de Lima e Silva wrote:
>
> This looks like an issue to be addressed at PEP-8 since it looks like 
> a styling issue.
>
> I haven't seen any other recommendations there on how to use a certain 
> data structure, though.
>
> Cheers, Leandro
>
> Em 17/04/2014 16:24, "Guido van Rossum" <guido at python.org 
> <mailto:guido at python.org>> escreveu:
>
>     It's definitely something that should be put in some
>     documentation, 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
>     <mailto: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
>         <mailto: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 <http://python.org/%7Eguido>)
>
>
>

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