[Python-Dev] (no subject)

[Ian Lee]

I split off a separate thread on python-ideas [1] specific to the idea of
introducing "+" and "+=" operators on a dict.

[1] https://mail.python.org/pipermail/python-ideas/2015-February/031748.html


~ Ian Lee

On Tue, Feb 10, 2015 at 10:35 PM, John Wong <gokoproject at gmail.com> wrote:

>
>
> On Wed, Feb 11, 2015 at 12:35 AM, Ian Lee <ianlee1521 at gmail.com> wrote:
>
>> +1 for adding "+" or "|" operator for merging dicts. To me this operation:
>>
>> >>> {'x': 1, 'y': 2} + {'z': 3}
>> {'x': 1, 'y': 2, 'z': 3}
>>
>> Is very clear.  The only potentially non obvious case I can see then is
>> when there are duplicate keys, in which case the syntax could just be
>> defined that last setter wins, e.g.:
>>
>> >>> {'x': 1, 'y': 2} + {'x': 3}
>> {'x': 3, 'y': 2}
>>
>> Which is analogous to the example:
>>
>> new_dict = dict1.copy()
>> new_dict.update(dict2)
>>
>>
>> Well looking at just list
> a + b yields new list
> a += b yields modified a
> then there is also .extend in list. etc.
>
> so do we want to follow list's footstep? I like + because + is more
> natural to read. Maybe this needs to be a separate thread. I am actually
> amazed to remember dict + dict is not possible... there must be a reason
> (performance??) for this...
>
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