issue_comments: 431973631

Confirmed as fixed:

```python

In [1]: import xarray impor In [2]: import numpy

In [3]: xarray.DataArray(numpy.arange(3), dims=("x",), coords={"x": {"a", "b", "c"}}) ...:

TypeError Traceback (most recent call last) <ipython-input-3-6d18e1623a15> in <module> ----> 1 xarray.DataArray(numpy.arange(3), dims=("x",), coords={"x": {"a", "b", "c"}})

~/workspace/xarray/xarray/core/dataarray.py in init(self, data, coords, dims, name, attrs, encoding, fastpath) 225 226 data = as_compatible_data(data) --> 227 coords, dims = _infer_coords_and_dims(data.shape, coords, dims) 228 variable = Variable(dims, data, attrs, encoding, fastpath=True) 229

~/workspace/xarray/xarray/core/dataarray.py in _infer_coords_and_dims(shape, coords, dims) 62 if utils.is_dict_like(coords): 63 for k, v in coords.items(): ---> 64 new_coords[k] = as_variable(v, name=k) 65 elif coords is not None: 66 for dim, coord in zip(dims, coords):

~/workspace/xarray/xarray/core/variable.py in as_variable(obj, name) 88 elif isinstance(obj, (set, dict)): 89 raise TypeError( ---> 90 "variable %r has invalid type %r" % (name, type(obj))) 91 elif name is not None: 92 data = as_compatible_data(obj)

TypeError: variable 'x' has invalid type <class 'set'> ```

The original issue is https://github.com/pydata/xarray/issues/1691, and includes why we raise rather than coerce to an array