Please, let me explain once more what want. I need a JSON codec (serializer-deserializer), which can preserve its input on its output. After some thought it seems to be really concerning only the floats. (The attempt to generalize this should be regarded as secondary - just suggestion subject to comments).
What you, Andrew and possibly Chris have probably understood is that I was asking for a JSON codec which would ensure the same bit to bit (or byte to byte) output with any other JSON codec out there. This never was my point, as, in my first post, in this thread, I already gave an example of two different serializers which give different results and invalidate directly such a request. And, as Chris pointed out in one of his replies, it is simply matter of choice and none is either "right" or "wrong". Second, the fact that the JSON codec (I am looking for) should be able to preserve its inputs in its outputs byte-to-byte does not necessarily mean that the (default) standard implementation must do that. As, again using the same example I gave above, I am fine with default implementation, which chooses platform native binary float for the JSON float representation and is as such subject to the consequences already discussed here. The only thing what my "request" requires from the standard module is to allow serialize decimal.Decimal or, in broader scope, some custom type in a way that it can preserve its input in its output byte-to-byte. And this and only this is exactly the kind of byte-to-byte precision I need from the implementation. Or better say I need an adequate support from the standard implementation that it should be possible. After thinking it through, it seems to me that the current implementation with JSONEncoder.default override satisfies this requirement for any custom type, except decimal.Decimal, because of how it handles the custom value provided by custom serializer and because decimal.Decimal is in fact a representation of the native JSON type (float). There is no way to serialize the float, which was deserialized into decimal.Decimal as a float again and have the exactly same value (literally) in the output as was in the input. Serializing it into custom map or a string might acceptable for some other application (though one would wonder why to do that to something which is by nature a native JSON type with perfectly valid representation of its own), but is not acceptable in my case for reasons stated above. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/7HTES3EHGB2NMDTSGLN5HZCBYGX5FB74/ Code of Conduct: http://python.org/psf/codeofconduct/
