دکوراتور پایتون چیست؟

def uppercase_decorator(func):
    def wrapper():
        result = func()
        return result.upper()
    return wrapper

def say_hello():
    return "hello world"

# Manually applying decorator
say_hello = uppercase_decorator(say_hello)

print(say_hello())  # Output: "HELLO WORLD"

def uppercase_decorator(func):
    def wrapper():
        result = func()
        return result.upper()
    return wrapper

@uppercase_decorator  # ✅ This automatically applies the decorator
def say_hello():
    return "hello world"

print(say_hello())  # Output: "HELLO WORLD"

@uppercase_decorator
def say_hello():
    return "hello world"

def log_decorator(func):
    def wrapper(*args, **kwargs):
        print(f"Calling {func.__name__} with {args} {kwargs}")
        result = func(*args, **kwargs)
        print(f"{func.__name__} returned {result}")
        return result
    return wrapper

@log_decorator
def add(a, b):
    return a + b

add(5, 3)

Calling add with (5, 3) {}
add returned 8

from fastapi import FastAPI, Depends, HTTPException

app = FastAPI()

def auth_required(func):
    def wrapper(username: str):
        if username != "admin":
            raise HTTPException(status_code=403, detail="Unauthorized")
        return func(username)
    return wrapper

@app.get("/secure-data")
@auth_required  # ✅ Protects this route
def secure_data(username: str):
    return {"message": "Secure data accessed!"}

# Now only "admin" can access this route

import time

def time_it(func):
    def wrapper(*args, **kwargs):
        start_time = time.time()
        result = func(*args, **kwargs)
        end_time = time.time()
        print(f"{func.__name__} took {end_time - start_time:.4f} seconds")
        return result
    return wrapper

@time_it
def slow_function():
    time.sleep(2)
    return "Finished"

slow_function()

slow_function took 2.0001 seconds