[Python-Dev] PySequence_Concat for dicts

[Jared Flatow]

On Jan 11, 2008, at 6:45 PM, Raymond Hettinger wrote:
> IMO, the chainmap() recipe on ASPN is a much better solution since  
> it doesn't create a third dictionary with the all the attendant  
> allocation and copying effort.

I wasn't suggesting that the result of concatenation would be a  
chained table, rather that it would perform the equivalent of an  
update and return the new dict (the same way extend works for lists).

> It isn't a common use case to need to sum two dictionaries while  
> keeping both of the inputs unaltered.

Inplace concatenation could be implemented more efficiently but would  
be exactly the same as calling update.

jared