الأنماط في Python

import time
from functools import wraps

def log_execution(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        print(f"تشغيل: {func.__name__}")
        start = time.time()
        result = func(*args, **kwargs)
        duration = time.time() - start
        print(f"انتهى في {duration:.2f} ثانية")
        return result
    return wrapper

@log_execution
def process_order(order_id: int):
    time.sleep(1)
    return {"order_id": order_id, "status": "completed"}

class DatabaseConnection:
    def __enter__(self):
        print("فتح اتصال بقاعدة البيانات")
        self.conn = {"connected": True}
        return self.conn

    def __exit__(self, exc_type, exc_val, exc_tb):
        print("إغلاق الاتصال")
        self.conn["connected"] = False
        if exc_type:
            print(f"حدث خطأ: {exc_val}")

# الاستخدام
with DatabaseConnection() as db:
    print(db)
# يتم إغلاق الاتصال تلقائياً بعد الخروج من with

# باستخدام contextlib
from contextlib import contextmanager

@contextmanager
def transaction():
    print("بدء المعاملة")
    try:
        yield
        print("تنفيذ المعاملة (commit)")
    except:
        print("إلغاء المعاملة (rollback)")
        raise

class SingletonMeta(type):
    _instances = {}

    def __call__(cls, *args, **kwargs):
        if cls not in cls._instances:
            cls._instances[cls] = super().__call__(*args, **kwargs)
        return cls._instances[cls]

class Logger(metaclass=SingletonMeta):
    def log(self, message: str):
        print(f"[LOG] {message}")

logger1 = Logger()
logger2 = Logger()
print(logger1 is logger2)  # True

class JSONMixin:
    def to_json(self) -> str:
        import json
        return json.dumps(self.__dict__)

class LoggingMixin:
    def log(self, message: str):
        print(f"[{self.__class__.__name__}] {message}")

class User(JSONMixin, LoggingMixin):
    def __init__(self, name: str, email: str):
        self.name = name
        self.email = email

user = User("أحمد", "ahmed@example.com")
print(user.to_json())
user.log("مستخدم جديد تم إنشاؤه")

from abc import ABC, abstractmethod
from typing import Protocol

# باستخدام Abstract Base Classes
class PaymentProcessor(ABC):
    @abstractmethod
    def pay(self, amount: float) -> bool:
        pass

class CreditCardPayment(PaymentProcessor):
    def pay(self, amount: float) -> bool:
        print(f"دفع {amount} عن طريق بطاقة ائتمان")
        return True

# باستخدام Protocol (duck typing)
class Drawable(Protocol):
    def draw(self) -> None: ...

class Circle:
    def draw(self) -> None:
        print("رسم دائرة")

def render(shape: Drawable):
    shape.draw()