Python "why" questions

[Thomas Jollans]

On 08/07/2010 03:38 PM, Steven D'Aprano wrote:
> On Sat, 07 Aug 2010 14:00:59 +0200, Thomas Jollans wrote:
> 
>> On 08/07/2010 05:05 AM, Default User wrote:
>>> >From "the emperor's new clothes" department:
>>>
>>> 1)  Why do Python lists start with element [0], instead of element [1]?
>>> "Common sense" would seem to suggest that lists should start with [1].
>>
>> As others have pointed out, there is a nice argument to be made for
>> zero-based indices. However, the killer reason is: "it's what everybody
>> else does." 
> 
> I'll have you know that there are still some Pascal programmers in the 
> world, thank you.
> 
> 
> 
>> As it stands, the only perceived problem with zero-based
>> indices is that it's one of the many tiny confusions that new
>> programmers face. On the other hand, it's the way nearly every other
>> popular programming language does it, and therefore, it's the way almost
>> every programmer likes to think about sequences.
> 
> It didn't take me long to get used to thinking in zero-based indexes, but 
> years later, I still find it hard to *talk* in zero-based indexes. It's 
> bad enough saying that the first element in a list in the zeroth element, 
> but that the second element is the first makes my head explode... 

zeroth
oneth
twoth
 ;-)

(element no. one is a better way of pronouncing it.)

> 
> 
>> Also, it has the nice property that, for an infinite sequence, every
>> integer makes sense as an index (in Python).
> 
> Er, what's the -1th element of an infinite sequence?

well, it's the first from the other end. The infinite bit is in between,
thank you very much. ;-)