[Python-Dev] Third milestone of FAT Python

[Victor Stinner]

2015-12-15 22:10 GMT+01:00 Franklin? Lee <leewangzhong+python at gmail.com>:
> (Stealing your style of headers.)

I'm using reStructured Text, it's not really a new style :-)


> Overhead
> ========
>
> If inner functions are being created a lot, that's extra work. But I
> guess you should expect a lot of overhead if you're doing such a
> thing.

Sorry, I didn't read carefully your email, but I don't think that it's
acceptable to make Python namespaces slower. In FAT mode, we need
versionned dictionaries for module namespace, type namespace, global
namespace, etc.


>> Do you have an estimation of the cost of the "extra pointer"? Impact
>> on memory and CPU. dict is really a very important type for the
>> performance of Python. If you make dict slower, I'm sure that Python
>> overall will be slower.
>
> I'm proposing it as a subclass.

Please read the "Versionned dictionary" section of my email:
https://mail.python.org/pipermail/python-dev/2015-December/142397.html

I explained why using a subclass doesn't work in practice.

Victor