Why is splat operator (*) only used for method parameters?

Question

In python, I can use the splat operator to unpack a list and send the list items as arguments to a function

dirs = ['this','is','a','file','path']
path = os.path.join(*dirs)
# path is now 'this/is/a/file/path'

My question is, why is this feature limited to method params?

For example, the following is invalid syntax:

x = [1,2,3]
y = [0,*x,4,5]

Why doesn't this result in [0,1,2,3,4,5]?

It's a valid syntax in Python 3.5 and newer. – vaultah May 04 '17 at 21:36 — vaultah, May 04 '17 at 21:36
Wow, they were really quick to implement my suggestion! :) – JordanC May 04 '17 at 21:39 — JordanC, May 04 '17 at 21:39

score 4 · Accepted Answer · answered May 04 '17 at 21:39

4

As mentioned, it is valid syntax as of Python 3.5+:

>>> x = [1,2,3]
>>> y = [0,*x,4,5]
>>> y
[0, 1, 2, 3, 4, 5]

answered May 04 '17 at 21:39

brianpck

1 Answers1