On 2006-04-25, Schüle Daniel <[EMAIL PROTECTED]> wrote:
>> I'm not familiar with Tkinter, but it seems as thought with 2,
>> the "image" variable is garbage collected after the
>> constructor of Main is called. With 1, you save a reference to
>> the image, so it does not get garbage collected.
Correct.
> image is local variable of imageLabel
Actually it's a parameter to the constructor that was called to
create the "imageLabel" object.
> I would expect that in case imageLabel lives, it should hold
> alife objects bound to its local variables
It would. Therefore the "image" object apparently isn't bound
to a local variable in the object imageLabel.
> I am just curious *why* reference to image is not hold by
> imageLabel which on his part is hold by frame1...
Good question. Untold millions of programmers have tripped
over that bug. Well, would you believe untold dozens? I know
I did. It's a common enough problem that it's given special
mention in a couple books on Tkinter.
My _guess_ is that this is one of the misfeatures resulting
from the way Tkinter is implimented: it's not a real binding of
Python to the tk library. It's a Python wrapper around a TCL
interpreter which is bound to the tk library (or something like
that). This results in some counter-intuitive (non-pythonic)
behaviors like the one you discovered with bitmap images and
labels.
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