Python给函数加上状态的多种方式小结

def my_function():
    print(f"Current count is {my_function.counter}")
    my_function.counter += 1

# 初始化函数属性
my_function.counter = 0

# 调用函数
my_function()  # 输出：Current count is 0
my_function()  # 输出：Current count is 1
my_function()  # 输出：Current count is 2

def make_counter():
    count = 0
    
    def counter():
        nonlocal count  # 修改外部变量
        print(f"Current count is {count}")
        count += 1
    
    return counter

# 创建一个带有状态的计数器函数
my_counter = make_counter()

# 调用计数器函数
my_counter()  # 输出：Current count is 0
my_counter()  # 输出：Current count is 1
my_counter()  # 输出：Current count is 2

class Counter:
    def __init__(self):
        self.count = 0
    
    def __call__(self):
        print(f"Current count is {self.count}")
        self.count += 1

# 创建一个计数器实例
my_counter = Counter()

# 调用类实例
my_counter()  # 输出：Current count is 0
my_counter()  # 输出：Current count is 1
my_counter()  # 输出：Current count is 2

def with_counter(func):
    func.counter = 0
    
    def wrapper(*args, **kwargs):
        print(f"Current count is {wrapper.counter}")
        result = func(*args, **kwargs)
        wrapper.counter += 1
        return result
    
    wrapper.counter = 0
    return wrapper

@with_counter
def my_function():
    print("Function is called")

# 调用带有装饰器的函数
my_function()  # 输出：Current count is 0, Function is called
my_function()  # 输出：Current count is 1, Function is called
my_function()  # 输出：Current count is 2, Function is called