[Python-Dev] O(1) deletes from the front of bytearray (was: Re: Adding bytes.frombuffer() constructor to PEP 467 (was: [Python-ideas] Adding bytes.frombuffer() constructor)

[Chris Angelico]

On Wed, Oct 19, 2016 at 2:57 AM, Chris Barker - NOAA Federal
<chris.barker at noaa.gov> wrote:
>> The proposal is that it should be documented as being part of the
>> language spec starting in 3.4 (or whatever).
>
> Is the performance characteristics of any object part of the language spec?
>
> I.e if someone wrote an implementation with an O(n) insert dict, it
> would suck, but wouldn't it still be Python?

This exact question came up when MicroPython wanted to represent
Unicode strings internally as UTF-8. It was decided that having O(n)
indexing/slicing was acceptable, and was something that the
implementation could judge the value of. (Since uPy is designed for
smaller systems than CPython is, O(n) is less significant.)

ChrisA