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| -rw-r--r-- | doc/neps/nep-0034.rst | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/doc/neps/nep-0034.rst b/doc/neps/nep-0034.rst index 04eea2d64..4d113d7bd 100644 --- a/doc/neps/nep-0034.rst +++ b/doc/neps/nep-0034.rst @@ -24,9 +24,11 @@ Users who specify lists-of-lists when creating a `numpy.ndarray` via ``np.array`` may mistakenly pass in lists of different lengths. Currently we accept this input and create a ragged array with ``dtype=object``. This can be confusing, since it is rarely what is desired. Changing the automatic dtype -detection to never return ``object`` for ragged arrays will force users who -actually wish to create ``object`` arrays to specify that explicitly, see for -instance `issue 5303`_. +detection to never return ``object`` for ragged arrays (defined as a recursive +`sequence`_ of sequences, where not all the sequences on the same level have +the same length) will force users who actually wish to create ``object`` arrays +to specify that explicitly. Note that lists, tuples, and nd.arrays are all +sequences. See for instance `issue 5303`_. Usage and Impact ---------------- @@ -48,6 +50,12 @@ determine what shape is desired, one could use: >>> arr = np.empty(correct_shape, dtype=object) >>> arr[...] = values +We will also reject mixed seqeunces of ``non-sequence and sequence``, for instance +all of these will be rejected: + + >>> arr = np.array([np.arange(10), [10]]) + >>> arr = np.array([[range(3), range(3), range(3)], [range(3), 0, 0]]) + Related Work ------------ |