[Python-Dev] Dynamic module namspaces (original) (raw)

Johan Dahlin jdahlin at async.com.br
Mon Jul 17 15:41:30 CEST 2006

Andrew Bennetts wrote:

On Sat, Jul 15, 2006 at 03:38:04PM -0300, Johan Dahlin wrote:

In an effort to reduce the memory usage used by GTK+ applications written in python I've recently added a feature that allows attributes to be lazy loaded in a module namespace. The gtk python module contains quite a few attributes (around 850) of which many are classes or interfaces (150+) Have you seen the "demandload" hack that Mercurial uses? You can find it here: http://selenic.com/repo/hg?f=cb4715847a81;file=mercurial/demandload.py

It seems quite similar to Philips Importer, it's not completely solving the problem I'm having, since I do something like this:

class LazyNamespace(ModuleType): def init(self, realmodule, locals): attributes = {} for attr in realmodule._get_lazy_attribute_names(): attributes[attr] = None

    def __getattribute__(_, name):
        if name in attributes:
            value = realmodule._construct_lazy_attribute(name)
    ...
        return value

There are almost 1000 symbols in the gtk namespace, creating all of them at import time wastes memory and speed, while I've been mainly looking at the memory consumption speed will also benefit. Importing gtk at this point quite fast actually, less than 200ms on my fairly old box.

GUI programs does not need to be as responsive as command line applications as hg & bzr, users seems to accept that it takes a second or a few to start up a GUI application.

-- Johan Dahlin <jdahlin at async.com.br> Async Open Source

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