On Sat, 2025-04-12 at 10:10 +0000, Mateusz Sokol wrote: > Hi all! > > The Array API standard states that `T` property should only be > applied to 2-dimensional arrays, in all other cases it should raise > an error: > https://data-apis.org/array-api/latest/API_specification/generated/array_api.array.T > > To ensure that NumPy also follows this rule, I opened a PR that > raises a warning for `arr.T` for non-2-dimensional arrays and > scalars: https://github.com/numpy/numpy/pull/28678
There was once a surprising amount of resistance to doing this exact change a long time ago in NumPy and that is exactly why it never happened earlier and that is why we have `.mT` and not just `.T` to begin with. I am still happy with slowly deprecating it with a message to use `arr.transpose()`, `np.moveaxis()`, or `.mT` when it is applies. Maybe making sure that `.T` keeps working at least for 2-D, and think about what to do for 1-D (probably an error), although I am not sure about this unless there is a long term plan to consider allowing `.T` to mean the same as `.mT`. That sais, it is not correct to say there is any incompatibility! This is an opinionated recommendation at most and if it was more it would probably be a mistake there. - Sebastian > > For non-2-dimensional arrays, the replacement for `arr.T` can be > either: Array API compatible, namely `np.permute_dims(arr, > range(arr.ndim)[::-1])`, or shorter, NumPy specific: > `arr.transpose()`. > > The new discrepancy between `arr.T` and `arr.transpose()` is > justified, as `T` is defined by the Array API, where `transpose` > isn't and should retain the existing behavior. > > Please share your thoughts! > > Best regards, > Mateusz > _______________________________________________ > 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: sebast...@sipsolutions.net > _______________________________________________ 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
