Python Material - Part - 22 - Decorator

What is a Decorator?

A decorator is a wrapper around a function — it adds extra functionality without changing the original function!

☕ Think of it like: Sprinkling chocolate powder on coffee — The coffee is the same, but with extra decoration on top! 🍫

Basic Decorator example

def surendra(func):      # function తీసుకుంటుంది
    def wrapper():
        print("Before function runs")
        func()               # original function execute
        print("After function runs")
    return wrapper           # wrapper return చేస్తుంది


@surendra
def students_info():
    print("Meera sindhu")
    print("Narendra Boyina")

students_info()  # calling function


Advanced Decorator example:

from functools import wraps

"""A decorator that checks permission before allowing a function
 to run — only authorized users can execute it!
"""

"""@wraps(func) makes sure the original function's identity is never lost
even after being wrapped by a decorator"""

def require_admin(func):
    @wraps(func)
    def wrapper(user_role):
        if user_role != "admin": #Blocks anyone who is not admin
            print("Access denied: Admins only")
            return None
        else:
            return func(user_role) #Allows admin to run the function
    return wrapper

@require_admin
def acess_tea_inventory(role):
    print("Access granted to tea inventory")

acess_tea_inventory("user")# blocked
acess_tea_inventory("admin")  # allowed