西工大人工智能程序设计Python 西工大nojNOJ解答（1-60题，全套Python源码），开箱即用

# 装饰器没有参数时，最外层参数是func（被修饰函数），有参数时最外层是个带参数的装饰器，参数是n（该参数），里面再加一层装饰器，接受func参数。 ''' 1.函数装饰器 ''' # def count_call(func): # def wrapper(*args, **kwargs): # wrapper.call_count += 1 # result = func(*args, **kwargs) # print(f'function {func.__name__} has been called for {wrapper.call_count} times.') # return result # wrapper.call_count = 0 # 初始化wrapper函数的自定义属性call_count # return wrapper # # @count_call # def say_hello(): # print("hello a hello") # # say_hello() # say_hello() # say_hello() ''' 2.带参数的函数装饰器 ''' # def repeat(n): # 返回装饰器的装饰器，接收装饰器的参数 # def decoration(func): # 装饰器 # def wrapper(*args, **kwargs): # 被替换的函数 # result = None # for _ in range(n): # result = func(*args, **kwargs) # return result # 被替换函数的返回值 # return wrapper # 被替换函数 # return decoration # 装饰器 # # @repeat(3) # def say_hello(): # print("hello a hello") # # say_hello() ''' 3.类装饰器 ''' # class count_call: # def __init__(self, func): # self.func = func # self.call_count = 0 # # # 当一个对象实现了 __call__ 方法时，你就可以使用圆括号 () 来调用这个对象，就像调用一个普通函数一样。 # def __call__(self, *args, **kwargs): # self.call_count += 1 # result = self.func(*args, **kwargs) # print(f'function {self.func.__name__} has been called for {self.call_count} times.') # return result ''' 实际上，@count_call 等价于 say_hello = count_call(say_hello)。 count_call(say_hello) 创建了一个 count_call 类的实例，并将 say_hello 传递给 __init__ 方法。 say_hello 现在是一个 count_call 类的实例，而不是原来的函数。 ''' # @count_call # def say_hello(): # print("hello a hello") # # say_hello() # say_hello() # say_hello() ''' 4.带参数的类装饰器 ''' class count_call: def __init__(self, n): self.n = n # 传入参数 def __call__(self, func): # 注意在此处传入被替换函数 def wrapper(*args, **kwargs): result = None for _ in range(self.n): result = func(*args, **kwargs) return result return wrapper ''' 实际上，@count_call(3) 等价于 say_hello = count_call(3)(say_hello)。 count_call(3) 创建了一个 count_call 类的实例，并将 3 传递给 __init__ 方法。 count_call(3)(say_hello) 调用 count_call 类的 __call__ 方法，并将 say_hello 传递给 __call__ 方法。 __call__ 方法返回 wrapper 函数，say_hello 现在是一个 wrapper 函数，而不是原来的 say_hello 函数。 ''' @count_call(3) def say_hello(name): print(f"Hello, {name}") say_hello("Alice")