Mastering Python Decorators: A Complete Guide

Mastering Python Decorators: A Complete Guide 🔄

Decorators wrap functions or classes to extend behavior without modifying original code, boosting reusability and readability.

1. Basic Function Decorator

def my_decorator(func):
    def wrapper(*args, **kwargs):
        print("Before function call")
        result = func(*args, **kwargs)
        print("After function call")
        return result
    return wrapper

@my_decorator
def say_hello(name):
    print(f"Hello, {name}")

say_hello("Chulsoo")

2. Decorator with Arguments

def repeat(n):
    def decorator(func):
        def wrapper(*args, **kwargs):
            for _ in range(n):
                func(*args, **kwargs)
        return wrapper
    return decorator

@repeat(3)
def greet():
    print("Hello")

greet()  # Prints "Hello" 3 times

3. Class Decorator

def add_repr(cls):
    cls.__repr__ = lambda self: f"<{cls.__name__} {self.__dict__}>"
    return cls

@add_repr
class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

p = Person("Chulsoo", 30)
print(p)  # <Person {'name': 'Chulsoo', 'age': 30}>

Summary

• Decorators extend functionality by wrapping code.
• @ syntax applies them cleanly.
• Various use cases for function and class decorators exist.