[Tutor] program hangs in while loop using wx.yield

[Alan Gauld]

"Patty" <patty at cruzio.com> wrote

> then I went through Alan Gauld's tutorial which also helped.

Glad to hear it :-)

> If I just can't figure out how to do this with Tkinter and the 
> Python

I can send some basic code if that would help...


> Imaging Library, is 'wxPython' the additional software I would want 
> to install and try with?  Is its purpose to make GUI event 
> programming easier

No, in fact it is similar in concept to Tkinter but works in a style 
more
like most other GUI toolkits. It is also far more powerful with more 
widgets
and more complex styling tools and support for printing(as in paper).
Tkinter is catching up on the native look department through the new
ttk widgets but wxWidgets are nativbe from the ground up so they
will probably always look slightly more "natural".

But for your application wxPython and Tkinter should wind up looking
pretty much the same both in terms of code and end result,.

> feel bad about being confused?)  If so, can someone explain these 
> additional software packages out there?  I mean are they coming from 
> some third companies?  And why?  If the software is free.  I'm not 
> understanding the history or business part of these Python modules 
> and libraries.

Open source works like this: Somebody finds they need somethjing built
so they build it. Then they think, maybe other people could use this,
so they announce its availability (usually after polishing it a bit,
adding some comments etc) Other people start using it, they ask for
extra features, or they add some themselves and send it to the author.
Gradually a core team of developers forms and they start publishing
regular updates and bug fixes.

It is all very organic and apparently disorganised but it works most 
of the time.
Code that isn't very good but serves a need gradually gets improved
- or eventually rewritten from scratch - and code that is not really 
needed
tends to just wither and die from lack of support. Some projects grow
into huge undertakings like GNU and Linux and OpenOffice etc.
These might be sponsored by large (or small) companies providing
their paid staff to contribute to the project because they find it 
critical
to their business (so they want to ensure it stays viable) or they see
strategic advantage - eg Sun's support for OpenmOffice as
an alternative to MS Office...

Most of Python and its modules come from such a background.

> one organization who is discussing or approving standards for this 
> language?

There is a community which is loosely organised and a process
for submitting changes etc. How it works varies from project to 
project.
You can see it all in action if you visit SourceForge the home of many
OpenSource projects both large and small. But there is nothing like
the formalised standards surrounding languages like C or COBOL
or Java.

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/