[Python-ideas] Json object-level serializer

[Georg Brandl]

Am 29.07.2010 13:35, schrieb Tarek Ziadé:
> Hello,
> 
> What about adding in the json package the ability for an object to
> provide a different object to serialize ?
> This would be useful to translate a class into a structure that can be
> passed to json.dumps
> 
> So, it __json__ is provided, its used for serialization instead of the
> object itself:
> 
>>>> import json
>>>> class MyComplexClass(object):
> ....     def __json__(self):
> ....         return 'json'
> ....
>>>> o = MyComplexClass()
>>>> json.dumps(o)
> '"json"'

You can do this with a very short subclass of the JSONEncoder:

class MyJSONEncoder(JSONEncoder):
    def default(self, obj):
        return obj.__json__()  # with a useful failure message

I don't think it needs to be built into the default encoder.

Georg

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