[Python-Dev] Internal representation of strings and Micropython

[dw+python-dev at hmmz.org]

On Wed, Jun 04, 2014 at 03:17:00PM +1000, Nick Coghlan wrote:

> There's a general expectation that indexing will be O(1) because all
> the builtin containers that support that syntax use it for O(1) lookup
> operations.

Depending on your definition of built in, there is at least one standard
library container that does not - collections.deque.

Given the specialized kinds of application this Python implementation is
targetted at, it seems UTF-8 is ideal considering the huge memory
savings resulting from the compressed representation, and the reduced
likelihood of there being any real need for serious text processing on
the device.

It is also unlikely to find software or libraries like Django or
Werkzeug running on a microcontroller, more likely all the Python code
would be custom, in which case, replacing string indexing with
iteration, or temporary conversion to a list is easily done.

In this context, while a fixed-width encoding may be the correct choice
it would also likely be the wrong choice.


David