Python如何使类对象在函数间共享

class MyClass:
    shared_value = 10

    def my_method(self):
        print(self.shared_value)

obj1 = MyClass()
obj2 = MyClass()

print(obj1.shared_value)  # 输出: 10
print(obj2.shared_value)  # 输出: 10

obj1.shared_value = 20
print(obj1.shared_value)  # 输出: 20
print(obj2.shared_value)  # 输出: 10

# 使用装饰器实现单例模式
def singleton(cls):
    instances = {}

    def wrapper(*args, **kwargs):
        if cls not in instances:
            instances[cls] = cls(*args, **kwargs)
        return instances[cls]

    return wrapper

@singleton
class MyClass:
    shared_value = 10

    def my_method(self):
        print(self.shared_value)

obj1 = MyClass()
obj2 = MyClass()

print(obj1.shared_value)  # 输出: 10
print(obj2.shared_value)  # 输出: 10

obj1.shared_value = 20
print(obj1.shared_value)  # 输出: 20
print(obj2.shared_value)  # 输出: 20

shared_value = 10

def my_function():
    global shared_value
    print(shared_value)

my_function()  # 输出: 10

shared_value = 20
my_function()  # 输出: 20