On Aug 22, 11:18 am, David Moss <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I want to manage and control access to several important attributes in
> a class and override the behaviour of some of them in various
> subclasses.
>
> Below is a stripped version of how I've implemented this in my current
> bit of work.
>
> It works well enough, but I can't help feeling there a cleaner more
> readable way of doing this (with less duplication, etc).
>
> Is this as good as it gets or can this be refined and improved
> especially if I was to add in a couple more attributes some fairly
> complex over-ride logic?
>
> #!/usr/bin/env python
>
> class A(object):
> def __init__(self):
> self._x = None
> self._y = None
>
> def _set_x(self, value):
> self._x = value
>
> def _get_x(self):
> return self._x
>
> x = property(_get_x, _set_x)
>
> def _set_y(self, value):
> self._y = value
>
> def _get_y(self):
> return self._y
>
> y = property(_get_y, _set_y)
Within the bounds of Python, that's it.
In the cases where you're not executing code on 'get' or 'set', it
might be possible to have a default getter/setter, that just sets the
value of a variable name. This keeps your interface the same across
inheritance and changes. Possible to have it assign a default value
too.
def _set_z(self, value):
self._z = value
#def _get_z(self):
# return self._z
z = property( True, _set_z ) #still gets self._z
Unless, you are looking at something 'periodic' or regular. From
something I'm working on:
def _getbalance( self ):
return self._tree.geti(
self.where+ self.lookup[ 'balance' ] )
def _getparent( self ):
return self._tree.getI(
self.where+ self.lookup[ 'parent' ] )
Where 'balance' and 'parent' could both come from something generic:
balance= property( tree_lookup( 'balance' ) )
parent= property( tree_lookup( 'parent' ) )
They would have to take care to define 'self' properly and everything.
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