شرح مصممو بايثون: الدليل الكامل لعام 2026

@my_decoratorndef greet(name):n return f"Hello, {name}!"

greet = my_decorator(greet)

def log_calls(func):n """Decorator that logs function entry and exit."""n def wrapper(*args, **kwargs):n print(f"→ Calling {func.__name__} with args={args}, kwargs={kwargs}")n result = func(*args, **kwargs)n print(f"← {func.__name__} returned {result!r}")n return resultn return wrappernn@log_callsndef add(a, b):n return a + bnnadd(3, 4)n# Output:n# → Calling add with args=(3, 4), kwargs={}n# ← add returned 7

import functoolsnndef log_calls(func):n @functools.wraps(func) # ← copies __name__, __doc__, __module__, etc.n def wrapper(*args, **kwargs):n print(f"→ Calling {func.__name__}")n result = func(*args, **kwargs)n print(f"← {func.__name__} returned {result!r}")n return resultn return wrappernn@log_callsndef add(a, b):n """Add two numbers."""n return a + bnnprint(add.__name__) # 'add' ✅nprint(add.__doc__) # 'Add two numbers.' ✅

import functools, timenndef retry(times=3, delay=1.0, exceptions=(Exception,)):n """Retry a function up to `times` times on specified exceptions."""n def decorator(func):n @functools.wraps(func)n def wrapper(*args, **kwargs):n last_err = Nonen for attempt in range(1, times + 1):n try:n return func(*args, **kwargs)n except exceptions as e:n last_err = en print(f" Attempt {attempt}/{times} failed: {e}")n if attempt < times:n time.sleep(delay)n raise last_errn return wrappern return decoratornn@retry(times=3, delay=0.5, exceptions=(ConnectionError,))ndef fetch_data(url):n # simulate a flaky network calln raise ConnectionError("timeout")nntry:n fetch_data("https://api.example.com/data")nexcept ConnectionError:n print("All retries exhausted.")

import functools, timenndef timer(func):n @functools.wraps(func)n def wrapper(*args, **kwargs):n start = time.perf_counter()n result = func(*args, **kwargs)n elapsed = time.perf_counter() - startn print(f"{func.__name__} took {elapsed:.4f}s")n return resultn return wrappernndef log_calls(func):n @functools.wraps(func)n def wrapper(*args, **kwargs):n print(f"Calling {func.__name__}")n return func(*args, **kwargs)n return wrappernn@timer # applied second (outer)n@log_calls # applied first (inner)ndef process(n):n return sum(range(n))nnprocess(1_000_000)n# Output:n# Calling processn# process took 0.0312s

import functoolsnnclass CallCounter:n """Counts how many times a function is called."""n def __init__(self, func):n functools.update_wrapper(self, func)n self.func = funcn self.count = 0nn def __call__(self, *args, **kwargs):n self.count += 1n print(f"{self.func.__name__} called {self.count} time(s)")n return self.func(*args, **kwargs)nn@CallCounterndef say_hello(name):n print(f"Hello, {name}!")nnsay_hello("Alice") # called 1 time(s)nsay_hello("Bob") # called 2 time(s)nprint(say_hello.count) # 2

class Temperature:n _kelvin_offset = 273.15nn def __init__(self, celsius):n self._celsius = celsiusnn @propertyn def fahrenheit(self):n """Computed attribute — no () needed when accessing."""n return self._celsius * 9/5 + 32nn @fahrenheit.settern def fahrenheit(self, value):n self._celsius = (value - 32) * 5/9nn @classmethodn def from_kelvin(cls, kelvin):n """Factory method — creates instance from Kelvin."""n return cls(kelvin - cls._kelvin_offset)nn @staticmethodn def is_valid_celsius(value):n """Utility — no access to instance or class."""n return value >= -273.15nnt = Temperature(100)nprint(t.fahrenheit) # 212.0 (property)nt.fahrenheit = 32 # setternt2 = Temperature.from_kelvin(373.15) # classmethodnprint(Temperature.is_valid_celsius(-300)) # False (staticmethod)

from functools import lru_cachenn@lru_cache(maxsize=128)ndef fibonacci(n):n if n < 2:n return nn return fibonacci(n - 1) + fibonacci(n - 2)nnprint(fibonacci(50)) # Instant — cached resultsnprint(fibonacci.cache_info()) # CacheInfo(hits=48, misses=51, ...)

import functoolsnndef require_auth(func):n """Decorator for protected routes."""n @functools.wraps(func)n def wrapper(request, *args, **kwargs):n token = request.headers.get("Authorization", "")n if not token.startswith("Bearer "):n return {"error": "Unauthorized"}, 401n return func(request, *args, **kwargs)n return wrappernn@require_authndef get_user_profile(request):n return {"user": "Alice", "email": "alice@example.com"}

import functools, timenfrom collections import defaultdict, dequenndef rate_limit(calls=10, period=60):n """Allow at most `calls` per `period` seconds per caller."""n history = defaultdict(deque)n def decorator(func):n @functools.wraps(func)n def wrapper(*args, **kwargs):n now = time.time()n key = args[0] if args else "default" # use first arg as caller IDn q = history[key]n while q and now - q[0] > period:n q.popleft()n if len(q) >= calls:n raise RuntimeError(f"Rate limit exceeded: {calls} calls per {period}s")n q.append(now)n return func(*args, **kwargs)n return wrappern return decoratornn@rate_limit(calls=5, period=60)ndef send_email(user_id, message):n print(f"Email sent to {user_id}: {message}")

# ❌ Wrong — returns Nonendef broken(func):n def wrapper(*args, **kwargs):n func(*args, **kwargs) # no return!n return wrappernn# ✅ Correctndef fixed(func):n @functools.wraps(func)n def wrapper(*args, **kwargs):n return func(*args, **kwargs) # always returnn return wrapper