One possible alternative is to define beam.Flatten for a single collection
to be functionally equivalent to beam.FlatMap(lambda x: x), but that would
be a larger change and such behavior might need to be consistent across
SDKs and documented. Adding a default value is a simpler change.
I can also confirm that the usage
| 'Flatten' >> beam.FlatMap(lambda x: x)
is fairly common by inspecting uses of Beam internally.
On Thu, Mar 21, 2024 at 1:30 PM Robert Bradshaw via dev <dev@beam.apache.org>
wrote:
> IIRC, Java has Flatten.iterables() and Flatten.collections(), the first of
> which does what you want.
>
> Giving FlatMap a default arg of lambda x: x is an interesting idea. The
> only downside I see is a less clear error if one forgets to provide this
> (now mandatory) parameter, but maybe that's low enough to be worth the
> convenience?
>
> On Thu, Mar 21, 2024 at 12:02 PM Joey Tran <joey.t...@schrodinger.com>
> wrote:
>
>> That's not really the same thing, is it? `beam.Flatten` combines two or
>> more pcollections into a single pcollection while beam.FlatMap unpacks
>> iterables of elements (i.e. PCollection<Iterable<T>> -> PCollection<T>)
>>
>> On Thu, Mar 21, 2024 at 2:57 PM Valentyn Tymofieiev via dev <
>> dev@beam.apache.org> wrote:
>>
>>> Hi, you can use beam.Flatten() instead.
>>>
>>> On Thu, Mar 21, 2024 at 10:55 AM Joey Tran <joey.t...@schrodinger.com>
>>> wrote:
>>>
>>>> Hey all,
>>>>
>>>> Using an identity function for FlatMap comes up more often than using
>>>> FlatMap without an identity function. Would it make sense to use the
>>>> identity function as a default?
>>>>
>>>>
>>>>
>>>>
