triccare triccare wrote:
> Greetings,
>
> Apologies if this has shown up twice; I jumped the gun sending before
> confirming registration.
>
> I have a class that completely implements MutableMapping, meaning that all
> the abstract methods are implemented. However, the keys method no longer
> returns the keys, but simply a repr of the instance. Example is below.
> Same is true for the items method.
>
> It would seem that, if all the abstract methods have been implemented, the
> keys and items methods should be able to perform exactly like the native
> dict versions. There does not seem to be a need to override these methods.
>
> Thank you for your time.
> triccare
>
> Code:
>
> from collections import MutableMapping
>
> class MyDict(MutableMapping):
>
> def __init__(self, *args, **kwargs):
> self.data = dict(*args, **kwargs)
>
> def __getitem__(self, key):
> return self.data[self.__keytransform__(key)]
>
> def __setitem__(self, key, value):
> self.data[self.__keytransform__(key)] = value
>
> def __delitem__(self, key):
> del self.data[self.__keytransform__(key)]
>
> def __iter__(self):
> return iter(self.data)
>
> def __len__(self):
> return len(self.data)
>
> def __keytransform__(self, key):
> return key
>
> md = MyDict({'a': 1, 'b':2})
> md.keys()
> ==> KeysView(<keys.MyDict object at 0x105f7f7b8>)
Nope, that's exactly right. That's the python3 behavior.
>>> d = {'a': 1, 'b':2}
>>> d.keys()
dict_keys(['b', 'a'])
Keys returns a dedicated keys object now, not just a list. That thing
you got back isn't a repr string; it's the actual object. If it were a
string it'd be quoted.
Try list(md.keys()).
--
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
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