class Car(object):
    def __init__(self, model):
        self.model = model
    def __eq__(self, other):
        return self.model==other.model

my_car = Car('Mercedes')

my_list = [1, 3.14, 1, 0 , 0, 1, 'some_string', my_car]

Error:
AttributeError: 'int' object has no attribute 'model

def __eq__(self, other):
    return isinstance(other, self.__class__) and other.model == self.model

from functools import total_ordering


@total_ordering
class Car:
    def __init__(self, model):
        self.model = model

    def __gt__(self, other):
        """
        Always False until you find a solution to compare cars with numbers.
        """
        return False

    def __repr__(self):
        return f'{self.__class__.__name__}(model="{self.model}")'


class Bike(Car):
    pass


my_car = Car("Mercedes")
my_bike = Bike("Citybike")

# removed the str, becuase it does not make any sense to compare text to a number
my_list = [1, 3.14, 1, 0, 0, 1, my_car, my_bike]
my_list.sort()
print(my_list)

Output:
[Bike(model="Citybike"), Car(model="Mercedes"), 0, 0, 1, 1, 1, 3.14]

(Mar-08-2025, 02:21 PM)Gribouillis Wrote: Deanhistad's idea looks like the way to go, however it is seldom a good idea to define an __eq__() method in a class in Python. I think the real question is why do you want to define this method? What's the use case for this? Among other issues, you won't be able to insert Car instances into sets or use them as dictionary keys.

c1 = Car('Mercedes')
c2 = Car('BMW')

print(c1 == c2)

(Mar-08-2025, 07:01 PM)Tsotne Wrote: The use case is to make a comparison based on your defined criteria.

c1 = Car('Mercedes')
c2 = Car('BMW')

print(c1 == c2)

In addition I might have a list of various objects.

print(c1.model == c2.model)