python 類與對象 小魚兒

import random as r
class Fish:
    def __init__(self):
        self.x=r.randint(0,10)
        self.y=r.randint(0,10)

    def move(self):
        self.x -=1
        print("I am at:",self.x,self.y)

class Goldfish(Fish):
    pass

class Carp(Fish):
    pass

class Salmon(Fish):
    pass

class Shark(Fish):
    def __init__(self):
        self.hungry=True
        super().__init__()

    def eat(self):
        if self.hungry:
            print("My dream is eating day and day")
            self.hungry=False

        else:
            print("I'm not hungry....")