Multi-dimensional list initialization

MRAB python at mrabarnett.plus.com
Wed Nov 7 18:17:02 CET 2012


On 2012-11-07 05:05, Steven D'Aprano wrote:
> On Wed, 07 Nov 2012 00:23:44 +0000, MRAB wrote:
>
>>> Incorrect.  Python uses what is commonly known as call-by-object, not
>>> call-by-value or call-by-reference.  Passing the list by value would
>>> imply that the list is copied, and that appends or removes to the list
>>> inside the function would not affect the original list.  This is not
>>> what Python does; the list inside the function and the list passed in
>>> are the same list.  At the same time, the function does not have access
>>> to the original reference to the list and cannot reassign it by
>>> reassigning its own reference, so it is not call-by-reference semantics
>>> either.
>>>
>> I prefer the term "reference semantics".
>
>
> Oh good, because what the world needs is yet another name for the same
> behaviour.
>
> - call by sharing
> - call by object sharing
> - call by object reference
> - call by object
> - call by value, where "values" are references
>    (according to the Java community)
> - call by reference, where "references" refer to objects, not variables
>    (according to the Ruby community)
> - reference semantics
>
>
> Anything else?
>
> http://en.wikipedia.org/wiki/Evaluation_strategy#Call_by_sharing
>
The disadvantage of calling it "call by ..." is that it suggests that
you're just talking about calling functions.

What about binding in general, eg "x = y"? Does it make sense to still
call it "call by ..."?



More information about the Python-list mailing list