I'm trying to create a program that returns "emergency messages" using the Strategy Pattern. I'm building it in a more functional way in that instead of using abstract classes to define my functions, I just defined the functions and called those.

However, I get the error

TypeError: text_alarm() missing 1 required positional argument: 'message'

My code:

class EmergencyDrillBase(object):

    _alarm_behavior = None
    _suggested_message = None

    def __init__(self, name, description):
        self.name = name
        self.description = description

    def set_alarm_behavior(self, alarm_behavior):
        self._alarm_behavior = alarm_behavior

    def set_suggested_message(self, suggested_message):
        self._suggested_message = suggested_message


# define alarm behaviors
def text_alarm(message):
    print(f"This is a Text alarm with message: {message}")


# define suggested messages
def evacuate_message():
    return("Evacuate")


# define drills
class FireDrill(EmergencyDrillBase):

    _suggested_message = evacuate_message()
    _alarm_behavior = text_alarm()


    name = "Fire Drill"
    description = "Fire Drill Description"

    def __init__(self):
        super(FireDrill, self).__init__(FireDrill.name, FireDrill.description)

    def sound_alarm(self):
        self._alarm_behavior(self._suggested_message)

def mini_drill_simulator():
    fire_drill = FireDrill()
    fire_drill.sound_alarm()

if __name__ == "__main__":
    mini_drill_simulator()

Can anybody spot where my mistake is?

Expected outcome: print ("This is a Text alarm with message: Evacuate")

CodePudding user response：

I think that (at least) _alarm_behavior = text_alarm() should be _alarm_behavior = text_alarm and _suggested_message = evacuate_message() should be _suggested_message = evacuate_message and then the methods should be referred to as FireDrill._suggested_message and FireDrill._alarm_behavior.

So a problem is calling the method(s) instead of just referencing them.