Checking Scenic types in Python

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1

Hello, I’d like to use the equivalent of “isinstance” on Scenic types in Python. Is this possible? I have looked at some of the simulators and I see that I can add an attribute to each Scenic class for introspection. Is that the preferred way?

Instead, it would be nice to have a more direct approach, like the following:

In test.scenic:

class A:
    name: "a"
    # all derived classes have this attribue
    instanceOfA: None 

class B:
    name: "b"

class C(A):
    name: "c->a"

region = RectangularRegion((0, 0), 0, 10, 10)

new A on region
new B on region
new C on region

And then in test.py:

import scenic

# What I'd like to do:
# from test.scenic import A

scenario = scenic.scenarioFromFile("test.scenic")
scene, numIterations = scenario.generate()

for obj in scene.objects:

    # What I'd like to do:
    # if isinstance(obj, A):
    #   ...

    # What I have to do instead
    if hasattr(obj, "instanceOfA"):
        print("Houston, we have a 'A'!")
        print(obj)

Note the commented-out lines showing what I’d like to do.

The output should be:

Houston, we have a 'A'!
a
Houston, we have a 'A'!
c->a

Any help is appreciated, but in the meantime I’ll use attributes.