swift234

[gyb] Convert map object to list object

Python 2's map function [1] returns a list by default. Compared with
Python 3's map function [2] which returns an iterator (or map object).
The former is subscriptable, while the latter is not.

This patch explicitly converts the result of some map operations to be
a list. That way they have the same intended behaviour on both Python 2
and 3.

[1] https://docs.python.org/2/library/functions.html#map
[2] https://docs.python.org/3/library/functions.html#map