fruits.py

class Fruit:
    def __init__(self, colour):
        self.colour = colour
        
    def __hash__(self):
        return hash((self.__class__.__name__, self.colour))
    
    def __eq__(self, other):
        return type(self) == type(other) and self.colour == other.colour
    
    def __repr__(self):
        return '{} ({})'.format(self.__class__.__name__, self.colour)
        
class Apple(Fruit):
    pass

class Berry(Fruit):
    pass

from collections import Counter

fruits = [
    Apple('red'), Apple('green'), Berry('black'), Berry('red'),
    Berry('black'), Apple('red'), Berry('red'), Apple('green'),
    Berry('blue'), Apple('pink')
]
counts = Counter(fruits)
#Counter({Apple (green): 2,
#         Apple (pink): 1,
#         Apple (red): 2,
#         Berry (black): 2,
#         Berry (blue): 1,
#         Berry (red): 2})