Python star unpacking for version 2.7
in python 2.X, you can do:
c = (1, 2, 3)
a, b = c[0], c[1:]
as long as c
has at least one member it will work because if c
only has 1 thing in it c[1:]
is []
.
You should probably make sure there is at least one thing in c
though, or else c[0]
will raise an exception.
You could do something like:
try:
c = tuple(c)
a, b = c[0], c[1:]
except TypeError, IndexError:
# c is not iterable, or c is iterable, but it doesn't have any stuff in it.
# do something else
pass
(a,b) = (None, []) if not len(c) else (c[0], c[1:])
is also an option for handling the case where c is an empty sequence, although it won't distinguish between [None] and [] in terms as assignments to a, b. So use it with care, the try / except is probably best.
I can see no real difference between Python 3 and 2.7 when handling an empty container, but the nice thing about Python 3 here is it works with any iterable.
This works in 2.7 if you know c is a generator.
a,b = c.next(), c
But the full beauty of unpacking seems to require Python 3.