Sorting by item_in_another_list

[Delaney, Timothy (Tim)]

Fredrik Lundh wrote:

> Delaney, Timothy (Tim) wrote:
> 
>> This is a requirement for all implementations claiming to be 2.3 or
>> higher.
> 
> the language reference only guarantees this for CPython:
> 
>      The C implementation of Python 2.3 introduced a stable
>      sort() method, but code that intends to be portable across
>      implementations and versions must not rely on stability.

http://docs.python.org/lib/typesseq-mutable.html

(9) Starting with Python 2.3, the sort() method is guaranteed to be
    stable. A sort is stable if it guarantees not to change the
    relative order of elements that compare equal -- this is helpful
    for sorting in multiple passes (for example, sort by department,
    then by salary grade).

That says pretty strongly to me that it's part of the language
specification. And I'm pretty sure Guido said as much when he
pronounced.

Tim Delaney