I like this. while ideally, eval(repr(an_object)) == object, in practice this is already violated fro large arays -- so other than doctests, this shouldn't cause too many headaches.
-CHB On Mon, Sep 30, 2024 at 10:13 AM Marten van Kerkwijk <m...@astro.utoronto.ca> wrote: > Hi All, > > When the repr of an array is shown, currently the dtype and shape are > explicitly listed if these cannot be directly inferred from the list > that is shown, i.e., if the dtype is not float64 or int64, and if the > size of the array is zero, but the shape not the simple (0,). > > For instance, > > ``` > np.empty((10,2,0), dtype="i2") > array([], shape=(10, 2, 0), dtype=int16) > ``` > > I propose to also show the shape for the (rare) case that an array is > summarized, i.e., when it has more than the default threshold of 1000 > elements, and elements are replaced by `...`. The logic is that also in > that case it is no longer clear what the shape actually is, which is > useful information (e.g., if working in a notebook -- which is the > original use case at https://github.com/numpy/numpy/issues/27461). > > I have a PR for that at https://github.com/numpy/numpy/pull/27482 > which would lead to the following: > > ``` > np.arange(1001) > array([ 0, 1, 2, ..., 998, 999, 1000], shape=(1001,)) > ``` > > Just to be sure: this PR causes *no* change for any arrays with sizes > less than a 1000, so I do not believe this change will lead to a lot of > unnecessary churn for down-stream packages. Indeed, between numpy and > astropy (which has lots of doctests), the only changes to (doc)tests > that were needed are the very few for arrays where the "threshold" is > explicitly exceeded. > > One irritant is that the shape is not an argument that can be passed in > to an `np.array` call. While this is just as much the case for > zero-sized arrays, perhaps a better solution would be to move the shape > information out of the parentheses, e.g., using ``...) # shape=(...)``. > I can change the PR to do that if that's the consensus. > > All the best, > > Marten > _______________________________________________ > 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: chris.bar...@noaa.gov > -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov
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