print(dog.__dict__.items() ^ cat.__dict__.items())

结果：

{('attitude', 'bow to me'), ('sound', 'meow'), ('sound', 'bark')}

对于类集合对象，^是对称差。

您可以查看一下DeepDiff。
在同一类的两个示例之间：

from deepdiff import DeepDiff
from pprint import pprint

class Animal:
    pass

dog = Animal()
cat = Animal()

dog.kingdom = 'mammal'
dog.sound = 'bark'

cat.kingdom = 'mammal'
cat.sound = 'meow'
cat.attitude = 'bow to me'

differences = DeepDiff(dog, cat)
pprint(differences)
>> {'attribute_added': [root.attitude],
>>  'values_changed': {'root.sound': {'new_value': 'meow', 'old_value': 'bark'}}}

在不同类的两个示例之间：

from deepdiff import DeepDiff
from pprint import pprint

class Dog:
    pass

class Cat:
    pass

dog = Dog()
cat = Cat()

dog.kingdom = 'mammal'
dog.sound = 'bark'

cat.kingdom = 'mammal'
cat.sound = 'meow'
cat.attitude = 'bow to me'

differences = DeepDiff(dog, cat, ignore_type_in_groups=(Dog, Cat))
pprint(differences)
>> {'attribute_added': [root.attitude],
>>  'values_changed': {'root.sound': {'new_value': 'meow', 'old_value': 'bark'}}}