sorting on keys in a list of dicts

[Tim Peters]

[Nick Coghlan]
...
> Python 2.3 has a stable sort, and Python 2.4 brought the guarantee that it shall
> remain that way. I'm not sure about Python 2.2 and earlier.

No list.sort() implementation before 2.3 was stable.  It was
confusing, though, because the samplesort/binary_insertion_sort hybrid
Python used for the 4 years preceding 2.3 *was* stable for all "small
enough" lists.  More than one person got fooled by guessing that
stability observed in small test cases meant it was always stable.