英文文档：
globals()- Return a dictionary representing the current global symbol table. This is always the dictionary of the current module (inside a function or method, this is the module where it is defined, not the module from which it is called).
- 说明：
- 1. 返回当前作用域内全局变量的字典。
>>> globals() {'__spec__': None, '__package__': None, '__builtins__': <module 'builtins' (built-in)>, '__name__': '__main__', '__doc__': None, '__loader__': <class '_frozen_importlib.BuiltinImporter'>} >>> a = 1 >>> globals() #多了一个a {'__spec__': None, '__package__': None, '__builtins__': <module 'builtins' (built-in)>, 'a': 1, '__name__': '__main__', '__doc__': None, '__loader__': <class '_frozen_importlib.BuiltinImporter'>}