英文文档：
locals()
update and return a dictionary representing the current local symbol table. free variables are returned by locals() when it is called in function blocks, but not in class blocks.
说明：
1. 函数功能返回当前作用域内的局部变量和其值组成的字典，与globals函数类似(返回全局变量)
>>> locals() {'__package__': none, '__loader__': , '__doc__': none, '__name__': '__main__', '__builtins__': , '__spec__': none} >>> a = 1 >>> locals() # 多了一个key为a值为1的项 {'__package__': none, '__loader__': , 'a': 1, '__doc__': none, '__name__': '__main__', '__builtins__': , '__spec__': none}
2. 可用于函数内。
>>> def f(): print('before define a ') print(locals()) #作用域内无变量 a = 1 print('after define a') print(locals()) #作用域内有一个a变量，值为1 >>> f >>> f() before define a {} after define a {'a': 1}
3. 返回的字典集合不能修改。
>>> def f(): print('before define a ') print(locals()) # 作用域内无变量 a = 1 print('after define a') print(locals()) # 作用域内有一个a变量，值为1 b = locals() print('b[a]: ',b['a']) b['a'] = 2 # 修改b['a']值 print('change locals value') print('b[a]: ',b['a']) print('a is ',a) # a的值未变 >>> f() before define a {} after define a {'a': 1} b[a]: 1 change locals value b[a]: 2 a is 1 >>>