It looks like I am resurrecting an old item, but I have been just hit by this and was directed to this issue (https://mail.python.org/archives/list/python-ideas@python.org/thread/WT6Z6YJDEZXKQ6OQLGAPB3OZ4OHCTPDU/)

I wonder if adding something similar to what `simplejson` uses (i.e. explicitly specifying in `json.dump(s)` how to serialize `decimal.Decimal`) could be acceptable.

Or, the other idea would be to expose a method in JSONEncoder, which would accept "raw" textual output, i.e. string (or even `bytes`) and would encode it without adding additional characters to it. (as explained in my posts in the other threads).

As it seems right now, there is no way to serialize `decimal.Decimal` the same way it is deserialized, i.e. while preserving the (arbitrary) precision.