Maciej Fijalkowski wrote:
For example other python implementations might decide to use python version as long as builtin version does not appear. Python versions are usually also better targets for jit than mixed versions. C level versions also usually have more bugs (just statistics), so some people might want to choose pure-python version.
In general - some people have some reasons.
Although nobody has broken "sys.modules['_decimal'] = 0", so deliberately turning off optimisations is pretty easy if you really don't want them.
There's a reason we moved to implicit import of optimised versions in Py3k - we're unlikely to revert to the old way of doing things.
As far as decimal.py in particular goes, there are significant maintenance gains in keeping a lot of the non-performance critical context management code in pure Python. So we're likely to wait and see how much speed Mark can wring out of a simple C decimal coefficient object (that other implementations can also fairly easily provide natively) before looking seriously at a wholesale replacement of the module.
Cheers, Nick.