jsonpickle returns False on check instance

Question

I wonder why the jsonpickle-module when consecutively applying or calling encode & decode does not pass the isinstance(...) check in Python 3.8.

Let say i have a simple class Person.

Here some code to illustrate what i mean:

import jsonpickle


class Person:
    id: int = -1
    name: str = "John Doe"

    def __init__(self, pId: int = None, name: str = None) -> None:
        self.id = (pId, self.id)[pId is None]
        self.name = (name, self.name)[name is None]


testInstance = Person()
testInstanceJSON = jsonpickle.encode(testInstance, unpicklable=True, make_refs=True)
print(testInstanceJSON)
testInstanceObject = jsonpickle.decode(testInstanceJSON)
print(testInstanceObject)
print(isinstance(testInstanceObject, Person.__class__))

It returns False on the last print-command!

Answer 1

The attribute __class__ of an object provides the class the object is an instance of.

Classes like Person are also objects and instances of type.

This means that

isinstance(testInstanceObject, Person.__class__)

is the same as

isinstance(testInstanceObject, type)

but of course testInstanceObject is not an instance of type.

Change it to

isinstance(testInstanceObject, Person)

to check if testInstanceObject is an instance of Person.