jfl | JavaScript Standard Functional Library | Code Inspection library

splder only supports scalar splines (interpolating a function y = f(x) with splrep), not vector splines obtained with splprep. In any case, you don't need it: just use the der parameter of splev:

I would first make a generic solution, then optionally optimize if the types of the top-levels of the JSON file are all the same (i.e. all object/dict, or all array/list).

If you have a mix of top-level types after loading (dict, list, value), you are not going to be able to combine them anyway. You can only combine them if every loaded data is a dict or every loaded is a list. If you have a combination or if you have one or more values at the toplevel, you cannot combine.

The generic approach is to have create an empty list and .append() the data loaded by json.load() to it, while keeping track of having, dict, list or values: