Pre-PEP: Dictionary accumulator methods

[Colin J. Williams]

Paul Rubin wrote:
> "El Pitonero" <pitonero at gmail.com> writes:
> 
>>What about no name at all for the scalar case:
>>
>>a['hello'] += 1
>>a['bye'] -= 2
> 
> 
> I like this despite the minor surprise that it works even when
> a['hello'] is uninitialized.
+1
and if the value is a list:
a['hello']= [1, 2, 3]
a['hello']+= [4]            # adding the brackets is a lot simpler than
                               typing append or extend.

Any user is free to add his/her own subclass to handle defaults.

Colin W.