如何创建冷却装饰器

Question

我正在尝试在Python中创建一个冷却装饰器3。理想的用法如下：

@cooldown(duration=2)
def func(string):
  print(string)

然后...

func('1st attempt') # should work (as cooldown == 0) and reset cooldown (cooldown = 2)
func('2nd attempt') # should fail (as cooldown != 0)
func.update_cooldown() # should decrease cooldown (cooldown -= 1)
func('3rd attempt') # should also fail (as cooldown != 0)
func.update_cooldown() # should decrease cooldown (cooldown -= 1)
func('4th attempt') # should work (as cooldown == 0) and reset cooldown (cooldown = 2)

我的代码(Python 3.8):

import functools

def cooldown(duration):
    def decorator(method):
        cooldown = 0

        @functools.wraps(method)
        def wrapper(*args, **kwargs):
            nonlocal cooldown
            if cooldown <= 0:
                cooldown = duration
                return method(*args, **kwargs)
            print(f'Cooldown active, {cooldown} updates remaining')

        return wrapper
    return decorator

我如何添加减少特定装饰功能的冷却时间计数器的功能？我将如何调整它以使用 class 方法？

提前致谢！

Answer 1

def cooldown(duration):
    def decorator(method):
        cooldown = 0

        @functools.wraps(method)
        def wrapper(*args, **kwargs):
            nonlocal cooldown
            if cooldown <= 0:
                cooldown = duration
                return method(*args, **kwargs)
            print(f"Cooldown active, {cooldown} updates remaining")

        def update_cooldown():
            nonlocal cooldown
            cooldown -= 1

        wrapper.update_cooldown = update_cooldown
        return wrapper

    return decorator

cooldown 每个装饰函数的变量都是唯一的，因为在每次冷却调用中你定义了新的装饰函数 def decorator(method):，以及新的冷却计数器。

它已经适用于类方法：

class A:
    @classmethod
    @cooldown(duration=2)
    def a(cls):
        print("whatever")

A.a() # whatever
A.a() # Cooldown active, 2 updates remaining
A.a.update_cooldown() 
A.a() # Cooldown active, 1 updates remaining

如何创建冷却装饰器

How to create a cooldown decorator

python

decorator

python-3.x

python-decorators