I don’t know javascript, so I can’t help you there.
You are either replicating the same output that javascript does (JSON, as created entirely by python), or formatting the data into objects that javascript will read (then convert to JSON? 
) .
I think a clear direction needs to be chosen one way or the other, since you cant mix them together?
@p.colbert and I seem to see this as an ETL problem, not a javascript problem I guess? 