List As An Entry In A Dict Not Json Serializable

I need to save a list (or a numpy array) as one of the entries in a JSON file. I am getting the “not JSON-serializable” error, and I can’t figure out how to fix it (and also

Solution 1:

It looks like there is a bug in numpy caused by a lack of flexibility in Python's json module. There is a decent workaround in that bug report:

>>>import numpy, json>>>defdefault(o):...ifisinstance(o, numpy.integer): returnint(o)...raise TypeError...>>>json.dumps({'value': numpy.int64(42)}, default=default)
'{"value": 42}'

Essentially, json.dumps() takes a default argument:

default(obj) is a function that should return a serializable version of obj or raise TypeError. The default simply raises TypeError.

The workaround posted just passed a function to json.dumps() that converts numpy.integer values to int.