Datasets more robust to non-string keys

setup.cfg

@@ -8,6 +8,7 @@ testpaths=xarray/tests
 [flake8]
 max-line-length=79
 ignore=
+  W503
 exclude=
   doc/
 

xarray/core/dataarray.py

@@ -466,7 +466,17 @@ def _getitem_coord(self, key):
         return self._replace_maybe_drop_dims(var, name=key)
 
     def __getitem__(self, key):
-        if isinstance(key, basestring):
+        try:
+            is_coord_key = any([
+                isinstance(key, basestring),
+                key in set(self.dims).union(self.coords)
+            ])
+        except TypeError:
+            # not hashable, but testing with collections.Hashable is not
+            # complete, since# tuples with slices inside will suggest
+            # they're hashable
+            is_coord_key = False
+        if is_coord_key:
             return self._getitem_coord(key)
         else:
             # xarray-style array indexing

xarray/tests/test_dataarray.py

@@ -17,8 +17,8 @@
 from xarray.core.pycompat import OrderedDict, iteritems
 from xarray.tests import (
     ReturnItem, TestCase, assert_allclose, assert_array_equal, assert_equal,
-    assert_identical, raises_regex, requires_bottleneck, requires_dask,
-    requires_scipy, source_ndarray, unittest, requires_cftime)
+    assert_identical, raises_regex, requires_bottleneck, requires_cftime,
+    requires_dask, requires_scipy, source_ndarray, unittest)
 
 
 class TestDataArray(TestCase):

xarray/tests/test_dataset.py

@@ -4181,6 +4181,12 @@ def test_dir_non_string(data_set):
     result = dir(data_set)
     assert not (5 in result)
 
+    # GH2172
+    sample_data = np.random.uniform(size=[2, 2000, 10000])
+    x = xr.Dataset({"sample_data": (sample_data.shape, sample_data)})
+    x2 = x["sample_data"]
+    dir(x2)
+
 
 def test_dir_unicode(data_set):
     data_set[u'unicode'] = 'uni'