python – 在dict理解中订阅locals()失败,KeyError

参见英文答案 > Python dictionary comprehension using locals() gives KeyError????????????????????????????????????2个
我被Python locals()的奇怪行为所困惑.
基本上我想从字典理解中获取locals()字典中的一个项目,但它失败了.这是一个非常基本的事情,所以：

>>> foo=123
>>> bar=345
>>> baz=678
>>> {k: locals()[k] for k in ('foo','bar','baz')}
Traceback (most recent call last):
  File "<stdin>",line 1,in <module>
  File "<stdin>",in <dictcomp>
KeyError: 'foo'
>>> locals()['foo']
123
>>> locale=locals()
>>> {k: locale[k] for k in ('foo','baz')}
{'foo': 123,'bar': 345,'baz': 678}
>>> type(locals())
<class 'dict'>
>>> def fun():
...     return {'foo': 123,'bar':345}
... 
>>> {k: fun()[k] for k in ('foo','bar')}
{'foo': 123,'bar': 345}

在实际的一面,在dict或字符串.format()中的丑陋{‘foo’：foo,’bar’：bar}等工作正常.
只是我错过了一些东西,所以知道为什么会增加我的编码chi(截至目前我在编码时不发光).

>>> _ = {k: print(locals()) for k in ('foo','baz')}
{'k': 'foo','.0': <tuple_iterator object at 0x7fdf840afa90>}
{'k': 'bar','.0': <tuple_iterator object at 0x7fdf840afa90>}
{'k': 'baz','.0': <tuple_iterator object at 0x7fdf840afa90>}

>>> _ = [locals()[k] for k in ('foo','baz')]
>>> _
[20,40,60]