On Oct 15, 2016 6:42 PM, "Steven D'Aprano" <steve@pearwood.info> wrote:
> doesn't make sense, it is invalid. Call it something else: the new
> "flatten" operator:
>     [^t for t in iterable]
> for example, which magically adds an second invisible for-loop to your list comps:

This thread is a lot of work to try to save 8 characters in the spelling of `flatten(it)`. Let's just use the obvious and intuitive spelling.

We really don't need to be Perl. Folks who want to write Perl have a perfectly good interpreter available already.

The recipes in itertools give a nice implementation:

def flatten(listOfLists):
    "Flatten one level of nesting"
    return chain.from_iterable(listOfLists)