[EMAIL PROTECTED] wrote:
> I want to inherit fresh copies of some class variables. So I set up a
> metaclass and meddle with the class variables there.
>
> Now it would be convenient to run thru a dictionary rather than
> explicitly set each variable. However getattr() and setattr() are out
> because they chase the variable thru the class hierarchy.
getattr() does, setattr() doesn't.
> Is there an easy way around this? Or am I stuck listing out the
> variables one per line?
>
> class SetClassVars(type):
> cvars = dict(name=None, desc=None, required=True, minlen=1,
> maxlen=25, idDown=999999999, idNext=0)
> def __init__(cls, name, bases, dict):
> if not cls.__dict__.has_key('name'): cls.name = None
> if not cls.__dict__.has_key('desc'): cls.desc = None
> if not cls.__dict__.has_key('required'): cls.required = True
> if not cls.__dict__.has_key('minlen'): cls.minlen = 1
> if not cls.__dict__.has_key('maxlen'): cls.maxlen = 25
> if not cls.__dict__.has_key('idDown'): cls.idDown = 999999999
> if not cls.__dict__.has_key('idNext'): cls.idNext = 0
Does this do what you want? Note that I don't even bother with __dict__
since the class dict is already available as the final argument to __init__.
>>> class SetClassVars(type):
... cvars = dict(name=None, desc=None, required=True)
... def __init__(cls, name, bases, classdict):
... for name, value in SetClassVars.cvars.iteritems():
... if not name in classdict:
... setattr(cls, name, value)
...
>>> class C(object):
... __metaclass__ = SetClassVars
... name = 'foo'
...
>>> class D(C):
... __metaclass__ = SetClassVars
... desc = 'bar'
...
>>> print C.name, C.desc, C.required
foo None True
>>> print D.name, D.desc, D.required
None bar True
STeVe
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