Returning 'None' on Instantiation ?
MarkH at ActiveState.com
Fri Jun 1 15:41:45 CEST 2001
Dave Haynes wrote:
> Is there a way to optionally return 'None' on instantiation?
> I'm thinking of something like the following:
> class myClass:
> def __init__(self, param):
> if <check param>:
> <initialise data members>
> <make self a 'None object'>
The "best" way IMO is to raise an exception here:
if <check param:
raise ValueError, "param a is wrong"
Then your caller has access to the specific problem:
inst = myClass(foo)
except ValueError, why:
print "Error making instance:", why
inst = None
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