Does Python cache the startup module?

[Baz Walter]

Fredrik Lundh <fredrik <at> pythonware.com> writes:

> 
> Baz Walter wrote:
> 
> > It's hard to supply an example for this, since it is local to the machine I 
am 
> > using. The startup module would look something like this:
> 
> would look, or does look?  if it doesn't look like this, what else does 
> it contain?

What I did was create a minimal version of the module which still exhibits the 
same behaviour (for me, that is). Basically, QWidget in the example below 
replaces my MainWindow class.
 
> > #!/usr/local/bin/python
> > 
> > if __name__ == '__main__':
> >     
> >     import sys
> >     from qt import QApplication, QWidget
> > 
> >     application = QApplication(sys.argv)
> >     mainwindow = QWidget()
> >     application.setMainWidget(mainwindow)
> >     mainwindow.show()
> >     sys.exit(application.exec_loop())
> > 
> > If I change the name 'mainwindow' to 'mainwidget', the widget it refers to 
does 
> > not get destroyed; when I change it back again, it does get destroyed. 
> > Otherwise, the program runs completely normally.
> 
> I don't see any code in there that destroys the widget, and I also don't 
> see any code in there that creates more than one instance of the main 
> widget.

Qt will try to destroy all widgets that are linked together in the object 
hierarchy.
 
> what do you do to run the code, and how to you measure leakage?

I run it with:

python app.py -widgetcount

The widgetcount switch is a Qt facility which counts how many widgets are 
created and how many destroyed.

Before changing the name 'mainwindow' to 'mainwidget' it reports:

Widgets left: 0    Max widgets: 2
Widgets left: 0    Max widgets: 149 (full program)

Afterwards it reports:

Widgets left: 1    Max widgets: 2
Widgets left: 146    Max widgets: 149 (full program)

> is the name "mainwidget" used for some other purpose in your application?

No