def get_eakon_instance_by_model(model_name) -> HVAC:
"""
A helper function to instantiate a new class using a model name.
:param model_name:
:return:
"""
model_name = model_name.lower()
class_name = model_name.capitalize()
try:
module_type = import_module(name=f"eakon.{model_name}")
model_class = getattr(module_type, class_name)
return ABC.register(type(class_name, (model_class, ), {}))()
except (ModuleNotFoundError, TypeError) as exc:
logging.debug("Exception was {}".format(exc))
raise NotImplementedError(
"No module {} implementing class {} was found. Model {} is unsupported."
.format(model_name, class_name, model_name))
price = 0
if car.kilometers_since_break_change > 10000:
# do work
car.kilometers_since_break_change = 0
price = 1000
if self.next:
return price + self.next.get_cost(car)
return price
# This is the sender that will send messages to the handler.
class Garage:
def __init__(self, maintenance):
self.maintenance = maintenance
def get_cost(self, car):
return self.maintenance.get_cost(car)
# Register classes
ABC.register(ChangeOil)
ABC.register(ChangeBreak)
# Example of the chain starting.
car = Car(6000, 15000)
maintenance = ChangeOil()
maintenance.set_next(ChangeBreak())
garage = Garage(maintenance)
print(garage.get_cost(car))
