[Python-ideas] Adding "+" and "+=" operators to dict

[Stephen J. Turnbull]

Donald Stufft writes:

 > Or we can choose the interpretation that has already been chosen by
 > multiple locations within Python. That keys are replaced and rhs
 > wins. This is consistent with basically every location in the stdlib
 > and Python core where two dicts get combined in some fashion other than
 > specialized subclasses.

Sure, nobody contests that we *can*.  To what benefit?  My contention
is that even the strongest advocates haven't come up with anything
stronger than "saves typing characters".

True, "dict = dict1 + dict2 + dict3" has a certain amount of visual
appeal vs. the multiline version, but you're not going to go beyond
that and write "dict = (dict1 + dict2)/2", or "dict = dict1 * dict2",
certainly not with "rightmost item wins" semantics.  So the real
competition for typing ease and readability is

    dict = merged(dict1, dict2, dict3)

and I see no advantage over the function version unless you think that
everything should be written using pseudo-algebraic operators when
possible.  And the operator form is inefficient for large dictionaries
(I admit I don't know of any applications where I'd care).