pydata / pydata/xarray

Inplace update fails with Implicit naming of numpy indexers

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topic-error reporting
Dominant language
Python
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Description

What happened?
import xarray as xr

x = xr.DataArray(np.zeros((2, 3)), dims=("a", "b"))
assert x[("b", np.array([0, 1, 0])),].shape == (3,)

x[("b", np.array([0, 1, 0])),] += 1  # ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.

Under the hood, this ends up being called, which fails:

x.variable[("b", np.array([0, 1, 0])),]

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the minimal reproducer and the x.variable[...] indexing path shown in the issue. Verify that the implicit NumPy indexer works for the inplace += case without the ValueError, while preserving the asserted (3,) shape.

Written by the indexing model from the issue text.

Assessment

Tech stack
numpy, python
Domain
data
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
48/100

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