PythonDùng ABC + @abstractmethod để tạo abstract class.
Class con bắt buộc implement tất cả abstract methods, nếu không sẽ không instantiate được.
python
from abc import ABC, abstractmethod
class Repository(ABC):
@abstractmethod
async def get_by_id(self, id: int): ...
@abstractmethod
async def create(self, data: dict): ...
def find_all(self): # Concrete method — có thể kế thừa
return self.get_all()
class UserRepository(Repository):
async def get_by_id(self, id): ... # Bắt buộc implement
async def create(self, data): ... # Bắt buộc implement
# Repository() # TypeError — cannot instantiate abstract classUse ABC + @abstractmethod.
Subclasses must implement all abstract methods or they cannot be instantiated.
python
from abc import ABC, abstractmethod
class Animal(ABC):
@abstractmethod
def speak(self) -> str: ...
class Dog(Animal):
def speak(self): return "Woof!"
# Animal() # TypeError — abstract class
Dog() # OK