issue_comments: 527245079

After digging a bit more into np.prod based on your comment, the situation is more complicated than I thought it was. I forgot that array.prod() has an implementation because pint has a ufunc implementation for it (so, actually np.prod(array) gives a result by way of __array_ufunc__ before https://github.com/hgrecco/pint/pull/764, but it no longer functions that way when __array_function__ is used). I hesitate to delegate to that implementation though, since it gives incorrect units when the axis and/or where arguments are used (see https://github.com/hgrecco/pint/issues/867).

array.any() and array.all() work now because they fall back to .any() and .all() on the magnitude; they aren't explicitly handled (or tested) by pint. Falling back to the magnitude here seems mostly fine, except possibly for offset units. Once a decision is made about the expected behavior in that case, I can add them to the __array_function__ list and add tests in pint.

Based on your tests and examples, I would agree that https://github.com/pydata/xarray/issues/3241 isn't really fixed. I also agree that adding the method tests is a good idea.

Thank you for clarifying about the sel/isel/loc tests. For some reason, I'm unfortunately getting results more consistent with the stripped unit behavior, rather than what your test results are showing. For example:

```python import xarray as xr import numpy as np import pint

unit_registry = pint.UnitRegistry()

array = np.linspace(5, 10, 20).astype(int) * unit_registry.m x = np.arange(len(array)) * unit_registry.s data_array = xr.DataArray(data=array, coords={"x": x}, dims=["x"])

print(data_array.sel(x = [15, 16] * unit_registry.volts)) outputs <xarray.DataArray (x: 2)> <Quantity([8 9], 'meter')> Coordinates: * x (x) int64 15 16 `` whereas it should be giving aKeyError` by your tests, if I'm interpreting them correctly. What happens in your environment when you run the above snippet?