python 跨类 全局变量 可变数据类型和不可变数据类型的作用机制

from dataclasses import dataclass

@dataclass
class A:
    def print(self):
        x.append(2)
        print(x)
@dataclass
class B:
    def print(self):
        print(x)

x = [1]
kwargs = {}
a = A(**kwargs)
b = B(**kwargs)
a.print()
b.print()

输出：[1, 2]

　　　[1, 2]

from dataclasses import dataclass

@dataclass
class A:
    global x
    x = 3
    def print(self):
        self.x = 2
        print(x)
@dataclass
class B:
    def print(self):
        print(x)

x = 1
kwargs = {}
a = A(**kwargs)
b = B(**kwargs)
a.print()
b.print()

输出：1

　　　1

from dataclasses import dataclass

@dataclass
class A:
    def print(self):
        global x
        x = 2
        print(x)
@dataclass
class B:
    def print(self):
        print(x)

x = 1
kwargs = {}
a = A(**kwargs)
b = B(**kwargs)
a.print()
b.print()

输出：2

　　　2

 以上测例都属于同一文件，跨文件传递变量，请搜索‘python 跨文件 全局 变量’