[Python-Dev] Tuple/list assignment question

[James Y Knight]

On Aug 3, 2004, at 2:44 AM, Dave Cole wrote:
> >>> a_list = [1, 2, 3, 4, 5]
> >>> a, b, *c = a_list

While you're proposing expanding the domain of the * construct of 
function calling to other parts of python, I'd also like to suggest the 
following features, to make the ** construct also applicable to the 
rest of the language.

To be read with an 70% wink. (I wouldn't be *un*happy if these were in 
python, but I am not seriously proposing these features for inclusion):

Dict unpacking, parallels current sequence unpacking:
 >>> d = {'foo': 1, 'bar': 2}
 >>> {'foo': x, 'bar': y} = d
 >>> x, y
(1, 2)

Dict interpolation, similar to sequence interpolation and keyword 
interpolation in function calls:
 >>> d = {'foo': 1, 'bar': 2}
 >>> d2 = {'baz': 3, **d}
 >>> d2
{'baz': 3, 'foo': 1, 'bar': 2}

Combining the two:
 >>> d = {'foo': 1, 'bar': 2, 'baz': 3}
 >>> {'foo': x, 'bar': y, **d2} = d
 >>> x, y, d2
(1, 2, {'baz': 3})

James