L4·OOP & Errors

🏛️Classes & Instances

Blueprints for objects with state and behavior.

classself__init__instance

§ 1Anatomy

class Name: body. __init__ initializes each new instance. self is the instance passed automatically.

§ 2Attributes

Instance attributes live on self. Class attributes are shared across instances.

§ 3Methods

Regular methods take self. @classmethod takes cls. @staticmethod takes neither.

Animated step-through

step 1 / 6// Dog('Fido', 3) — allocate + call __init__

1class Dog:
2    species = "Canis familiaris"  # class attr
3    def __init__(self, name, age):
4        self.name = name
5        self.age = age
6    def bark(self):
7        return f"{self.name} says woof"
8
9fido = Dog("Fido", 3)
10print(fido.bark())
11print(fido.species)

Variables

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Call stack

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Checkpoint quiz

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What does __init__ do?

Virtual Environments & pip

Inheritance & MRO