import inspect
import importlib
class_name = "FirstChildClass"
file_path = "/path/to/class.py"
try:
    spec = importlib.util.spec_from_file_location(class_name, file_path)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    for x in dir(module):
        obj = getattr(module, x)
        if inspect.isclass(obj) and (issubclass(obj, FirstParentClass) or issubclass(obj, SecondParentClass)) and obj.__name__ == class_name:
            return obj()
except ImportError as e:
    print(e)