issues: 532878771

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id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
532878771 MDU6SXNzdWU1MzI4Nzg3NzE= 3595 xr.Dataset.map drops attrs of DataArray 10194086 closed 0     6 2019-12-04T19:11:35Z 2020-10-14T16:29:52Z 2020-10-14T16:29:52Z MEMBER      

MCVE Code Sample

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

ds = xr.DataArray([1, 2], attrs=dict(tst="DataArray")).to_dataset(name="data") ds.attrs["tst"] = "Dataset" ds.map(np.mean, keep_attrs=True).data ```

returns python <xarray.DataArray 'data' ()> array(1.5)

Expected Output

python <xarray.DataArray 'data' ()> array(1.5) Attributes: tst: DataArray

Problem Description

Applying xr.Dataset.map(..., keep_attrs=True) does not retain the attributes of the DataArrays. Should it?

In constrast ds.mean(keep_attrs=True) retains DataArray-level attrs.

EDIT: corrected example

Output of xr.show_versions()

INSTALLED VERSIONS ------------------ commit: bd4f048bdb5a5a356a5603904d96a676037d1b6e python: 3.7.3 | packaged by conda-forge | (default, Jul 1 2019, 21:52:21) [GCC 7.3.0] python-bits: 64 OS: Linux OS-release: 4.12.14-lp151.28.32-default machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_GB.UTF-8 LOCALE: en_US.UTF-8 libhdf5: 1.10.5 libnetcdf: 4.6.2 xarray: 0.14.0+117.gbd4f048b.dirty pandas: 0.25.2 numpy: 1.17.3 scipy: 1.3.1 netCDF4: 1.5.1.2 pydap: installed h5netcdf: 0.7.4 h5py: 2.10.0 Nio: 1.5.5 zarr: 2.3.2 cftime: 1.0.4.2 nc_time_axis: 1.2.0 PseudoNetCDF: installed rasterio: 1.1.0 cfgrib: 0.9.7.2 iris: 2.2.0 bottleneck: 1.2.1 dask: 2.6.0 distributed: 2.6.0 matplotlib: 3.1.1 cartopy: 0.17.0 seaborn: 0.9.0 numbagg: installed setuptools: 41.6.0.post20191029 pip: 19.3.1 conda: None pytest: 5.2.2 IPython: 7.9.0 sphinx: None 
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   completed 13221727 issue

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