Metaclasses provide ultimate control over your architecture, making them a foundational component behind major enterprise Python frameworks such as Django, Pydantic, and SQLAlchemy. Summary Reference Table Python Tool Primary Benefit __slots__ Bypasses __dict__ to save memory on large-scale instances. Object Allocation __new__
In Python, classes are not just blueprints; they are first-class objects. Because they are objects, something must create them. That "something" is a metaclass. By default, the metaclass for all Python objects is type . Understanding type as a Callable
By default, Python uses the type metaclass to construct classes. However, you can write custom metaclasses to intercept, modify, validate, or register classes at the exact moment they are defined by the compiler. Creating a Custom Metaclass python 3 deep dive part 4 oop
Use __slots__ when you are creating where the set of attributes is strictly predefined (data processing pipelines, game entities, etc.).
: An instance method responsible for customizing the instance after it has been created. It receives the newly created object as self . Because they are objects, something must create them
@property def id(self): return self._id
class Animal: def __init__(self, name): self.name = name Understanding type as a Callable By default, Python
with ManagedFile('test.txt') as f: f.write('Hello')
In this example, the BankAccount class encapsulates the balance attribute and provides methods to access and modify it.