PyQt:如何在一个类中为其他类‘全局’定义？

class GlobalData:
    shared_variable = None

class ClassA:
    def __init__(self):
        self.data = GlobalData.shared_variable

class ClassB:
    def __init__(self):
        self.data = GlobalData.shared_variable

GlobalData.shared_variable = "Hello World"

a = ClassA()
b = ClassB()

print(a.data)  # 输出: Hello World
print(b.data)  # 输出: Hello World

class GlobalData:
    @classmethod
    def get_shared_variable(cls):
        return "Hello World"

class ClassA:
    def __init__(self):
        self.data = GlobalData.get_shared_variable()

class ClassB:
    def __init__(self):
        self.data = GlobalData.get_shared_variable()

a = ClassA()
b = ClassB()

print(a.data)  # 输出: Hello World
print(b.data)  # 输出: Hello World