On 12/15/2011 8:39 PM, Guido van Rossum wrote:
On Thu, Dec 15, 2011 at 5:16 PM, Terry Reedy <firstname.lastname@example.org mailto:email@example.com> wrote:
On 12/15/2011 3:42 PM, Ned Batchelder wrote: This is another place where Python is inconsistent. We're told, "lists are for homogenous sequences of varying length, like a C array; tuples are for heterogenous aggregations of known length, like a C struct." I have not been told that for several years, and I am pretty sure you will not find any such thing in the current docs. I consider it pretty much obsolete, as the differences that flowed from that idea are gone. In Python 3, tuples have all the non-mutating sequence methods that list does. The situation was much different in 1.4.
I strongly disagree. Being immutable sequences (i.e. homogeneous) is a minor secondary role for tuples. Their primary role remains to hold a small bunch of heterogeneous values -- like namedtuple, but without needing forethought. A good example are dictionary items -- these are (key, value) pairs where for a given dict, the keys are all of the same type (or of a small set of related types) and ditto for the values, but the key type and the value types are unrelated.
Could you explain why the foo(*args) syntax creates args as a tuple rather than a list?
-- --Guido van Rossum (python.org/~guido http://python.org/%7Eguido)
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