issues: 495198361

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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
495198361 MDU6SXNzdWU0OTUxOTgzNjE= 3317 Can't create weakrefs on DataArrays since xarray 0.13.0 167802 closed 0 6213168   8 2019-09-18T12:36:46Z 2019-10-14T21:38:09Z 2019-09-18T15:53:51Z CONTRIBUTOR      

MCVE Code Sample

python import xarray as xr from weakref import ref arr = xr.DataArray([1, 2, 3]) ref(arr)

Expected Output

I expect the weak reference to be created as in former versions

Problem Description

The above code raises the following exception: TypeError: cannot create weak reference to 'DataArray' object

Output of xr.show_versions()

INSTALLED VERSIONS ------------------ commit: None 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: 3.10.0-1062.1.1.el7.x86_64 machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_GB.UTF-8 LOCALE: en_GB.UTF-8 libhdf5: 1.10.4 libnetcdf: 4.6.2 xarray: 0.13.0 pandas: 0.25.1 numpy: 1.17.0 scipy: 1.3.0 netCDF4: 1.5.1.2 pydap: None h5netcdf: 0.7.4 h5py: 2.9.0 Nio: None zarr: None cftime: 1.0.3.4 nc_time_axis: None PseudoNetCDF: None rasterio: 1.0.22 cfgrib: None iris: None bottleneck: None dask: 2.3.0 distributed: 2.4.0 matplotlib: 3.1.1 cartopy: 0.17.0 seaborn: None numbagg: None setuptools: 41.2.0 pip: 19.2.3 conda: None pytest: 5.0.1 IPython: 7.8.0 sphinx: None 
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   completed 13221727 issue

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