Hi, For the sake of transparency, a short mailing list thread from November 2021 is here: https://mail.python.org/archives/list/numpy-discussion@python.org/thread/DNTC3A4CTVDYISVS57GXURJ6QP2PXPHK/ Corresponding (low-activity) feature request where you also commented: https://github.com/numpy/numpy/issues/20453
András On Sat, Jul 30, 2022, at 16:42, Matteo Santamaria wrote: > Hi all, > > I’d like to open a discussion on supporting callables within > `np.ndarray.__getitem__`. The intent is to make long function-chaining > expressions more ergonomic by removing the need for an intermediary, > temporary value. > > Instead of > > ``` > tmp = long_and_complicated_expression(arr) > return tmp[tmp > 0] > ``` > > we would allow > > ``` > return long_and_complicated_expression(arr)[lambda x: x > 0] > ``` > > This feature has long been supported by pandas’ .loc accessor, where > I’ve personally found it very valuable. In accordance with the pandas > implementation, the callable would be required to take only a single > argument. > > In terms of semantics, it should always be the case that `arr[fn] == > arr[fn(arr)]`. > > I do realize that expanding the API and supporting additional indexing > methods is not without cost, so I open the floor to anyone who’d like > to weigh in for/against the proposal. > > _______________________________________________ > NumPy-Discussion mailing list -- numpy-discussion@python.org > To unsubscribe send an email to numpy-discussion-le...@python.org > https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ > Member address: deak.and...@gmail.com _______________________________________________ NumPy-Discussion mailing list -- numpy-discussion@python.org To unsubscribe send an email to numpy-discussion-le...@python.org https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ Member address: arch...@mail-archive.com
