[Tutor] s.insert(i, x) explanation in docs for Python 3.4 confusing to me

[Alex Kleider]

On 2016-01-16 16:08, Alan Gauld wrote:
> On 16/01/16 23:56, Alan Gauld wrote:
>> On 16/01/16 22:39, boB Stepp wrote:
>> 
>>> So in this model of understanding negative list indexing, should it 
>>> be:
>>> 
>>> mylist = [ 100, 200, 300, 400, 500 ]
>>>           ^    ^    ^    ^    ^   ^
>>>           -5   -4   -3   -2   -1  ?
>>> 
>>> Well, it has to be this; otherwise, the off-by-one error exist.  This
>>> also continues to explain why
>>> 
>>> mylist.insert(-1, x)
>>> 
>>> inserts x *before* 500.  But in this model, what should go in the 
>>> place of "?"?
>> 
>> -0
>> 

alex at x301:~$ python3
Python 3.4.3 (default, Oct 14 2015, 20:33:09)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = [1, 2, 3, 4, 5]
>>> mylist[0:None]
[1, 2, 3, 4, 5]
>>> mylist[0:-0]
[]
>>> -0
0
>>> 

It appears that None provides a surrogate for -0 which itself evaluates 
to 0.


> 
> I should have added a :-/ to that in case it wasn't obvious...

It wasn't to me; could you please explain what you mean by ":-/" and/or 
where you should have added it?