[Tutor] Odd AttributeError

[Magnus Lyckå]

At 06:56 2003-05-21 -0700, Neil Hodge wrote:
>So, why does self.as_tuple not exist right after I defined it?  Thanks.

Because you didn't really define it? Is a __setattr__ method defined
for the class? Does it eat your definition?

See below:

 >>> class X:
...     def __init__(self, x):
...             self.x = x
...             print "self.x is", self.x
...     def __setattr__(self, attr, val):
...             pass
...
 >>> x = X(42)
self.x is
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File "<stdin>", line 4, in __init__
AttributeError: X instance has no attribute 'x'

You can try doing "self.__dict__['as_tuple'] = as_tuple" instead.
Then you avoid calling __setattr__ since you don't rebind any
attribute, just modify a current one.

 >>> class X:
...     def __init__(self, x):
...             self.__dict__['x'] = x
...             print "self.x is", self.x
...     def __setattr__(self, attr, val):
...             pass
...
 >>> x = X(42)
self.x is 42


--
Magnus Lycka (It's really Lyck&aring;), magnus@thinkware.se
Thinkware AB, Sweden, www.thinkware.se
I code Python ~ The shortest path from thought to working program