[ACCEPTED]-Using super() in nested classes-super
I'm not sure why A.B is not working correctly 2 for you, as it should.. Here's some shell 1 output that works:
>>> class A(object):
... class B(object):
... def __init__(self):
... super(A.B, self).__init__()
... def getB(self):
... return A.B()
...
>>> A().getB()
<__main__.B object at 0x100496410>
Since B will likely never be extended itself, this 1 should work:
class A(object):
class B(object):
def __init__(self):
super(self.__class__, self).__init__()
If the class A.B is unlikely to participate 9 in any multiple inheritance, then you're 8 better off just hard-coding the constructor 7 call:
class A(object):
class B(object):
def __init__(self):
object.__init__(self)
But if you really do need to have the 6 full power of super, then you can get what 5 you want by defining a custom descriptor 4 that will initialize the B attribute lazily:
class LazyAttribute(object):
def __init__(self, func, *args, **kwargs):
self._func = func
self._args = args
self._kwargs = kwargs
self._value = None
def __get__(self, obj, type=None):
if self._value is None:
print 'created', self._value
self._value = self._func(*self._args, **self._kwargs)
return self._value
class A(object):
class B(object):
def __init__(self):
super(A.B, self).__init__()
someattribute = LazyAttribute(B)
This 3 will cause the B attribute to be instantiated 2 the first time it's accessed, and then reused 1 thereafter:
>>> print A.someattribute
created <__main__.B object at 0x00AA8E70>
<__main__.B object at 0x00AA8E90>
>>> print A().someattribute
<__main__.B object at 0x00AA8E90>
For more info on descriptors, see: http://users.rcn.com/python/download/Descriptor.htm
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