Class Base1:
   Body of the class

Class Base2:
   Body of the class

Class Base3:
   Body of the class
.
.
.
Class BaseN:
   Body of the class

Class Derived(Base1, Base2, Base3, … , BaseN):
   Body of the class

class Animal:
   def eat(self):
      print("它吃昆虫。")
   def sleep(self):
      print("它在晚上睡觉。")

class Bird(Animal):
   def fly(self):
      print("它在天空中飞翔。")

   def sing(self):
      print("它唱歌。")
      print(issubclass(Bird, Animal))

Koyal= Bird()
print(isinstance(Koyal, Bird))

Koyal.eat()
Koyal.sleep()
Koyal.fly()
Koyal.sing()

True
它吃昆虫。
它在晚上睡觉。
它在天空中飞翔。
它唱歌。
True

class Base:
...

BaseAlias = Base
class Derived(BaseAlias):