Newbie getting confused again

[It's me]

If I have:

    a = (1,2,3)

how do I ended up with:

    res=[(1), (2), (3), (4), (5)]

without doing:

    res=[(a[0]), (a[1]), (a[2]), (4), (5)]

???

ps: This is just a nobrainer example of what my real code is trying to do.
"a" might have many many elements.   That's why the explicit indexing method
won't work.

Thanks,