List Behavior when inserting new items

[Bruno Desthuilliers]

Drew a écrit :
> I'm looking to add an element to list of items, however I'd like to 
> add it at a specific index greater than the current size:
> 
> list = [1,2,3]

NB: better to avoid using builtins types and functions names as identifiers.

> list.insert(10,4)
> 
> What I'd like to see is something like:
> 
> [1,2,3,,,,,,4]

Hint : the Python representation of nothing is a singleton object named 
None.

> However I see:
> 
> [1,2,3,4]

Yeps. I thought it would have raised an IndexError. But I seldom use 
list.insert() to append to a list - there's list.append() (and/or 
list.extend()) for this.

> Is there any way to produce this kind of behavior easily?

Hints:
 >>> [None] * 5
[None, None, None, None, None]
 >>> [1, 2, 3, None] + [10]
[1, 2, 3, None, 10]

HTH