import logging
import time
from functools import wraps
<p>logging.basicConfig(level=logging.INFO)</p><p>def log_execution(enabled=True):
def decorator(func):
@wraps(func)
def wrapper(*args, *<em>kwargs):
if not enabled:
return func(</em>args, **kwargs)</p><pre class="brush:php;toolbar:false"><code>        start = time.time()
        logging.info(f"→ 调用 {func.__name__}，参数: args={args}, kwargs={kwargs}")

        try:
            result = func(*args, **kwargs)
            elapsed = time.time() - start
            logging.info(f"✓ {func.__name__} 执行成功，耗时 {elapsed:.3f}s，返回: {result}")
            return result
        except Exception as e:
            elapsed = time.time() - start
            logging.error(f"✗ {func.__name__} 执行失败，耗时 {elapsed:.3f}s，错误: {e}")
            raise
    return wrapper
return decorator</code>

使用示例

@log_execution(enabled=True) def divide(a, b): return a / b

divide(10, 2) # 自动输出结构化日志

from functools import wraps
<p>def require_role(<em>allowed_roles):
def decorator(func):
@wraps(func)
def wrapper(</em>args, **kwargs):</p><h1>简单约定：第一个参数是 user 对象，含 role 属性</h1><pre class="brush:php;toolbar:false"><code>        if not args:
            raise ValueError("缺少 user 参数")

        user = args[0]
        if not hasattr(user, 'role') or user.role not in allowed_roles:
            raise PermissionError(f"拒绝访问：需要角色 {allowed_roles}，当前为 '{getattr(user, 'role', 'unknown')}'")

        return func(*args, **kwargs)
    return wrapper
return decorator</code>

使用示例

class User: def init(self, name, role): self.name = name self.role = role

@require_role('admin', 'editor') def publish_article(user, title): return f"已发布文章《{title}》"

admin = User("Alice", "admin") editor = User("Bob", "editor") guest = User("Charlie", "guest")

publish_article(admin, "Python 装饰器详解") # ✅ 成功 publish_article(guest, "新公告") # ❌ 抛出 PermissionError