python meta and __new__

meta.py

# Creating sigleton
class Singleton:
    _instance = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance

    def __init__(self):
        print("Initializing singleton...")

singleton1 = Singleton()
singleton2 = Singleton()

print(singleton1 is singleton2)  # Output: True


# Let's create with metaclass dictionary key 'my_attr' with key 42
class MyMeta(type):
    def __new__(cls, name, bases, attrs):
        attrs["my_attr"] = 42
        return super().__new__(cls, name, bases, attrs)

class MyClass(metaclass=MyMeta):
    pass

print(MyClass.my_attr)  # Output: 42