Python简单修饰符issu

Question

def my_decorator(some_function):
        print("Something is happening before some_function() is called.")
        some_function()
        print("Something is happening after some_function() is called.")

def just_some_function():
    print("Wheee!")

just_some_function = my_decorator(just_some_function)
just_some_function()

TypeError: 'NoneType' object is not callable 

我真的不明白，为什么这不管用？你知道吗

根据我的理解，一些函数基本上应该是这样的：

just_some_function():
        print("Something is happening before some_function() is called.")  
        print("Wheee!")  
        print("Something is happening after some_function() is called.")  

但是origional函数需要一个包装器函数才能工作，例如：

def my_decorator(some_function):
    def wrapper():
        print("Something is happening before some_function() is called.")
        some_function()
        print("Something is happening after some_function() is called.")
    return wrapper

为什么？有人能解释一下背后的逻辑吗？你知道吗

Answer 1

修饰符应该创建“替换”原有函数的新函数。你知道吗

def my_decorator(some_function):
        print("Something is happening before some_function() is called.")
        some_function()
        print("Something is happening after some_function() is called.")

此“decorator”返回None->；just \u some \u function=None->；TypeError:“NoneType”对象不可调用

def my_decorator(some_function):
    def wrapper():
        print("Something is happening before some_function() is called.")
        some_function()
        print("Something is happening after some_function() is called.")
    return wrapper

这个“decorator”返回包装器->；只是一些函数=包装器->；它的工作。你知道吗

你也可以查一下。试试print(just_some_function.__name__)->；“包装器”。你知道吗