Implementing Singleton pattern with Python

There are many ways to implement Singleton pattern in Python, and the following two common methods are given. 1. Use module level variables: python class Singleton: Single instance class def __new__(cls, *args, **kwargs): if not hasattr(cls, '_instance'): cls._instance = super().__new__(cls, *args, **kwargs) return cls._instance #Usage examples obj1 = Singleton() obj2 = Singleton() print(obj1 is obj2) # True 2. Use decorators: python def singleton(cls): instances = {} def wrapper(*args, **kwargs): if cls not in instances: instances[cls] = cls(*args, **kwargs) return instances[cls] return wrapper @singleton class Singleton: Single instance class pass #Usage examples obj1 = Singleton() obj2 = Singleton() print(obj1 is obj2) # True Both of the above methods can implement the Singleton pattern to ensure that there is only one instance in the program. The implementation principle is through rewriting`__ New__` Method to control the instantiation process and ensure that only one instance is created.