[Python-ideas] Allow using ** twice

[Ethan Furman]

On 06/06/2013 12:20 PM, Joao S. O. Bueno wrote:
> On 6 June 2013 13:43, Ethan Furman wrote:
>> On 06/06/2013 09:19 AM, Joao S. O. Bueno wrote:
>>>
>>> What if instead of simply checking if a key exists or not, these operators
>>> just operate themselves recursively into the values() ?
>>>
>>> It is not all unexpected, as "==" already does that -

I still don't understand this comment on '=='.


>>> so "dct3 = dct1 + dct2" would actually perform:
>>>
>>> dct3 = dct1.copy()
>>> for k, v in dct2.items():
>>>       dct3[k] = dct3[k] + v if k in dct3 else v
>>>
>>> -In that case, it would make more sense to make use of
>>> "or" instead of "|"  - although other binary logic and aritmetic
>>> operators could do the same.
>>>
>>> But that would bring no surprises to the already working-fine logic
>>> of counters.
>>
>>
>> No surprises?  What about when the function suddenly receives a list when it
>> wasn't expecting one?  Or did I totally misunderstand?
>
> That is no surprises - there won't be a list in there if it was not
> the programer's intention:
>
>>>> dict1["arg1"] = 5
>>>> dict2["arg1"] = 3
>>>> dict1 + dict2
> {"arg1": 8}

This strikes me as very surprising.  And what happens when arg1 is a str? Or some other interesting datatype?

-1 from me.

--
~Ethan~