The XAML editor gets this behaviour better than we do (IMO):

a_list = [<newline here>
....<next line here>

a_list = [1, <newline here>
..........<next line here>


I don't know about other's coding styles, but having:

a_list = [
..........1,
..........2,
..........]

doesn't work for me. I prefer:

a_list = [
....1,
....2,
]

Having to manually dedent the closing bracket is okay, and after bringing the first line back it's fine, but having the first only indent by 4 (indent size) would be handy.

(Same for tuples, dicts and calls, obviously. Now how do I mark this "super-low priority"...)