Quick survey: locals in comprehensions (Python 3 only)

[Tim Chase]

On 2018-06-23 23:08, Jim Lee wrote:
>>> On 06/23/2018 10:03 PM, Steven D'Aprano wrote:  
>>>> def test():
>>>>       a = 1
>>>>       b = 2
>>>>       result = [value for key, value in locals().items()]
>>>>       return result
>>>>
>>>> what would you expect the result of calling test() to be?
>>>  
>>> I would *expect* [1, 2, None], though I haven't actually tried
>>> running it. 
>> Interesting. Where do you get the None from?
>
> There are three locals:  a, b, and result. 

However at the time locals() is called/evaluated, "result" hasn't yet
been created/defined, so I wouldn't expect to see any representation
of "result" in the return value.  If it existed before the locals()
call, I would expect to see the value it had before the call:

  def test()
    a = 1
    b = 2
    result = "Steven"
    result = [value for key, value in locals().items()]
    return result
  test() # return [1, 2, "Steven"]


-tkc