>>> locals()
{'__package__': None, '__loader__': , '__doc__': None, '__name__': '__main__', '__builtins__': , '__spec__': None}

>>> a = 1

>>> locals() # 多了一個key為a值為1的項(xiàng)
{'__package__': None, '__loader__': , 'a': 1, '__doc__': None, '__name__': '__main__', '__builtins__': , '__spec__': None}

>>> def f():
 print('before define a ')
 print(locals()) #作用域內(nèi)無變量
 a = 1
 print('after define a')
 print(locals()) #作用域內(nèi)有一個a變量，值為1

 
>>> f

>>> f()
before define a 
{} 
after define a
{'a': 1}

>>> def f():
 print('before define a ')
 print(locals()) # 作用域內(nèi)無變量
 a = 1
 print('after define a')
 print(locals()) # 作用域內(nèi)有一個a變量，值為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的值未變

 
>>> f()
before define a 
{}
after define a
{'a': 1}
b["a"]: 1
change locals value
b["a"]: 2
a is 1
>>>