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Diffstat (limited to 'doc/release/upcoming_changes/22539.change.rst')
| -rw-r--r-- | doc/release/upcoming_changes/22539.change.rst | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/doc/release/upcoming_changes/22539.change.rst b/doc/release/upcoming_changes/22539.change.rst new file mode 100644 index 000000000..9df62be30 --- /dev/null +++ b/doc/release/upcoming_changes/22539.change.rst @@ -0,0 +1,19 @@ +``np.r_[]`` and ``np.c_[]`` with certain scalar values +------------------------------------------------------ +In rare cases, using mainly ``np.r_`` with scalars can lead to different +results. The main potential changes are highlighted by the following:: + + >>> np.r_[np.arange(5, dtype=np.uint8), -1].dtype + int16 # rather than the default integer (int64 or int32) + >>> np.r_[np.arange(5, dtype=np.int8), 255] + array([ 0, 1, 2, 3, 4, 255], dtype=int16) + +Where the second example returned:: + + array([ 0, 1, 2, 3, 4, -1], dtype=int8) + +The first one is due to a signed integer scalar with an unsigned integer +array, while the second is due to ``255`` not fitting into ``int8`` and +NumPy currently inspecting values to make this work. +(Note that the second example is expected to change in the future due to +:ref:`NEP 50 <NEP50>`; it will then raise an error.) |