[Python-Dev] (no subject) (original) (raw)

Ian Lee ianlee1521 at gmail.com
Wed Feb 11 08:24:33 CET 2015

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: newdict = dict1.copy() newdict.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... -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20150210/5bac4eb0/attachment.html>

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