What i'm trying to do is tie special methods of a "proxy" instance
to another instance:
def test1():
class Container:
def __init__( self, data ):
self.data = data
self.__getitem__ = self.data.__getitem__
data = range(10)
c = Container(data)
print "test1"
print c[3]
This works OK. But when I try the same thing on
new style classes:
def test2():
print "test2"
class Container(object):
def __init__( self, data ):
self.data = data
# self.__dict__["__getitem__"] = self.data.__getitem__
self.__setattr__( "__getitem__", self.data.__getitem__ )
data = range(10)
c = Container(data)
print
print c.__getitem__(3) # works OK
print c[3] # fails
I get a "TypeError: unindexable object". It
seems that c[] does not call __getitem__ in this case.
The plot thickens, however, when one tries the following:
def test3():
data = range(10)
c = type( "Container", (), { "__getitem__":data.__getitem__ } )()
print "test3"
print c[3]
Which works fine. However, if I need to resort to
such trickery, no-one here where i work will have any idea
what it does :)
Would anyone like to shed some light on what is going on here ?
bye,
Simon.
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