[Python-ideas] Reimplementing collections.deque as a dynamic array

[Julian Berman]

I've occasionally had a need for a container with constant-time append
to both ends without sacrificing constant-time indexing in the middle.
collections.deque will in these cases narrowly miss the target due to
linear indexing (with the current use case being for two deques
storing the lines of text surrounding the cursor in a text editor
while still being randomly indexed occasionally).

Wikipedia lists at least two common deque implementations:

http://en.wikipedia.org/wiki/Double-ended_queue#Implementations

where switching to a dynamic array would seemingly satisfy my requirements.

I know from a bit of experience (and a quick SO perusal) that "How do
I index a deque" does occasionally come up. Any thoughts on the value
of such a change?

JB