En Thu, 15 Mar 2007 09:01:07 -0300, <[EMAIL PROTECTED]> escribió:
> I got it to work, but I had to add a check to see if the class
> variable had been set..
> class Foo:
> baz = None
> def __init__(self):
> if Foo.baz == None:
> Foo.baz = True
> initBaz()
This is a different approach. You are using instance initialization
(Foo.__init__) to finish class initialization. Foo.__init__ will be called
each time you create a Foo instance; that's why you had to check if
Foo.baz is None.
(BTW, Foo.baz=True is unneeded).
The only problem I can see is that the Foo class is not completely
initialized until its first instance is created; this may not be a problem
in your case.
> What exactly is being accomplished by having the init function outside
> of the class? If there is no check, wouldn't it just execute every
> time an object is instantiated anyway?
What I intended was different:
==========
C:\TEMP>type foo.py
class Foo:
baz = None
def __init__(self):
pass
def initFoo():
import baz
Foo.baz = baz.Baz()
initFoo()
C:\TEMP>type bar.py
import foo
class Bar(foo.Foo):
pass
C:\TEMP>type baz.py
import bar
class Baz(bar.Bar):
pass
C:\TEMP>type test.py
import foo,bar,baz
print foo.Foo.baz
f = foo.Foo()
print f.baz
b = bar.Bar()
print b.baz
print baz.Baz.baz
C:\TEMP>python test.py
<baz.Baz instance at 0x00AD7B20>
<baz.Baz instance at 0x00AD7B20>
<baz.Baz instance at 0x00AD7B20>
<baz.Baz instance at 0x00AD7B20>
==========
initFoo is only executed when Foo is imported the first time. Note that
you can't do that if
> I thought it was a good design, but now I'm not so sure. I'm
> untrained, so often I dont know the right way to do things. As I
> build this into the libraries, I'll keep an eye on how the code is
> developing and go from there. Thanks for the help!
Usually Python code is quite concise and straightforward; when I find
myself writing things too convoluted, I know it's time to
refactor/redesign. (Anyway some things remain not as simple as I'd like
:( )
Perhaps you later find the need for a different/better way.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
