参考

1. https://blog.csdn.net/sakurainluojia/article/details/72783752
2. https://docs.python.org/3.6/tutorial/classes.html

概念

A scope is a textual region of a Python program where a namespace is directly accessible. “Directly accessible” here means that an unqualified reference to a name attempts to find the name in the namespace.

即可以在静态的作用域（本质是一段文本）中访问动态的命名空间（解释器启动时创建）

原文地址：https://www.cnblogs.com/allen2333/p/9072899.html