[Tutor] is it legal to have a class within a def

johnf jfabiani at yolo.com
Thu Jan 3 07:28:49 CET 2008

On Wednesday 02 January 2008 09:31:19 pm you wrote:
> johnf wrote:
> > def someMethod():
> >    class MyClass(object):
> >        .....
> >   if something:
> >      .....
> >      return someval
> Legal? Well the police won't come after you!
That's a good thing!
> Python allows a class statement anywhere. So this use is part of the
> language.
> So the question becomes "why would you want to do that?"
> Considerations:
> 1 - this usage creates a local object MyClass. The object will not be
> visible outside the function. The class definition is executed each time
> the function is called.
> 2 - the object could be returned or assigned to a global or added to a
> parameter that is a collection.
> 3 - if no instances are created in the function the object will
> disappear once the function execution ends.

1 and 3 are my reasons.  I'm creating a Dabo app.  When I attempted to create 
a special class that contained a dialog box I discovered that the dialog 
class created an indepentant type of window and allowed my program to 
continue running without waiting for the dialog to return a value first.  
However, I noticed if I created the dialog within a function my program 
stopped and waited until the dialog was closed to continue.   I think that I 
could define the Classes outside of the function and just import them when 
needed.  But then I wanted a self contained function so I asked why not place 
the class code in the function?  What is the difference?

John Fabiani

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