issues: 270440308

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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
270440308 MDU6SXNzdWUyNzA0NDAzMDg= 1681 Serializing attrs 2656596 closed 0     3 2017-11-01T20:24:48Z 2017-11-12T07:02:41Z 2017-11-12T07:02:41Z NONE      

I'm running Windows 10, Python 2.7, and xarray version 0.9.6

Using this dictionary for a Dataset attribute: ```python from xarray import Dataset

crs = {u'ellps': u'GRS80', u'k': 0.9996, u'lat_0': 0, u'lon_0': 173, u'no_defs': True, u'proj': u'tmerc', u'units': u'm', u'x_0': 1600000, u'y_0': 10000000}

ds = Dataset() ds.attrs['crs'] = crs ```

When attempting to serialize the dataset attribute, I get the

TypeError "Invalid value for attr: {u'lon_0': 173, u'k': 0.9996, u'ellps': u'GRS80', u'y_0': 10000000, u'no_defs': 'True', u'proj': u'tmerc', u'x_0': 1600000, u'units': u'm', u'lat_0': 0} must be a number string, ndarray or a list/tuple of numbers/strings for serialization to netCDF files"

This used to work in previous versions.

I then convert it to a list of tuples via crs.items(), and it successfully saves the netcdf. But when I then open the netcdf back up, the list of tuples become one long concatenated string. I'm guessing the core netcdf library has become more restrictive, but it would be nice to fully clarify what can be serialized or not.

Thanks

 
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