[WIP] Automate adding Dataset properties

datatree/datatree.py

@@ -99,112 +99,35 @@ def _map_over_subtree(tree, *args, **kwargs):
 class DatasetPropertiesMixin:
     """Expose properties of wrapped Dataset"""
 
-    # TODO a neater way of setting all of these?
     # We wouldn't need this at all if we inherited directly from Dataset...
 
+    def _add_dataset_properties(self):
+        for prop_name in _DATASET_PROPERTIES_TO_EXPOSE:
+            prop = getattr(Dataset, prop_name)
+
+        # Expose Dataset property
+        # TODO needs to be wrapped with a decorator that checks if self.has_data
+        # TODO should we be using functools.partialmethod here instead?
+        # TODO is the property() wrapper needed?
+        setattr(self, prop_name, property(prop))
+
+        # Copy the docstring across unchanged
+        prop_docstring = prop.__doc__
+        if prop_docstring:
+            dt_prop = getattr(self, prop_name)
+            setattr(dt_prop, '__doc__', prop_docstring)
+    """
+    This is the pattern we need to copy
+
     @property
     def dims(self):
         if self.has_data:
             return self.ds.dims
         else:
             raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def variables(self):
-        if self.has_data:
-            return self.ds.variables
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def encoding(self):
-        if self.has_data:
-            return self.ds.encoding
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def sizes(self):
-        if self.has_data:
-            return self.ds.sizes
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def attrs(self):
-        if self.has_data:
-            return self.ds.attrs
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-
-    @property
-    def nbytes(self) -> int:
-        return sum(node.ds.nbytes for node in self.subtree_nodes)
-
-    @property
-    def indexes(self):
-        if self.has_data:
-            return self.ds.indexes
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def xindexes(self):
-        if self.has_data:
-            return self.ds.xindexes
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def coords(self):
-        if self.has_data:
-            return self.ds.coords
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def data_vars(self):
-        if self.has_data:
-            return self.ds.data_vars
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    # TODO should this instead somehow give info about the chunking of every node?
-    @property
-    def chunks(self):
-        if self.has_data:
-            return self.ds.chunks
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def real(self):
-        if self.has_data:
-            return self.ds.real
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    @property
-    def imag(self):
-        if self.has_data:
-            return self.ds.imag
-        else:
-            raise AttributeError("property is not defined for a node with no data")
-
-    # TODO .loc
-
-    dims.__doc__ = Dataset.dims.__doc__
+
     variables.__doc__ = Dataset.variables.__doc__
-    encoding.__doc__ = Dataset.encoding.__doc__
-    sizes.__doc__ = Dataset.sizes.__doc__
-    attrs.__doc__ = Dataset.attrs.__doc__
-    indexes.__doc__ = Dataset.indexes.__doc__
-    xindexes.__doc__ = Dataset.xindexes.__doc__
-    coords.__doc__ = Dataset.coords.__doc__
-    data_vars.__doc__ = Dataset.data_vars.__doc__
-    chunks.__doc__ = Dataset.chunks.__doc__
-
+    """
 
 _MAPPED_DOCSTRING_ADDENDUM = textwrap.fill("This method was copied from xarray.Dataset, but has been altered to "
                                            "call the method on the Datasets stored in every node of the subtree. "
@@ -346,6 +269,9 @@ def __init__(
         self._add_all_dataset_api()
 
     def _add_all_dataset_api(self):
+        # Add properties like .dims
+        self._add_dataset_properties()
+
         # Add methods like .isel(), but wrapped to map over subtrees
         self._add_dataset_methods()