[Python-3000] Using *a for packing in lists and other places

Sat Mar 15 17:15:02 CET 2008

Thomas Wouters suggests some new syntax:
http://bugs.python.org/issue2292
>>> a, b, *c = range(5)

>>> *a, b, c = a, b, *c
>>> a, b, c
([0, 1, 2], 3, 4)
>>> [ *a, b, c ]
[0, 1, 2, 3, 4]
>>> L = [ a, (3, 4), {5}, {6: None}, (i for i in range(7, 10)) ]
>>> [ *item for item in L ]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Also, yielding everything from an iterator:
>>> def flatten(iterables):
... for it in iterables:
... yield *it
...
>>> L = [ a, (3, 4), {5}, {6: None}, (i for i in range(7, 10)) ]
>>> flatten(L)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
What do people think?
-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)