Add support for NDMeta

Author: Cadair

ndcube/asdf/converters/ndmeta_converter.py

@@ -0,0 +1,24 @@
+import numpy as np
+
+from asdf.extension import Converter
+
+
+class NDMetaConverter(Converter):
+    tags = ["tag:sunpy.org:ndcube/meta/ndmeta-*"]
+    types = ["ndcube.meta.NDMeta"]
+
+    def from_yaml_tree(self, node, tag, ctx):
+        from ndcube.meta import NDMeta
+        axes = {k: np.array(v) for k, v in node["axes"].items()}
+        meta = NDMeta(node["meta"], node["key_comments"], axes, node["data_shape"])
+        meta._original_meta = node["original_meta"]
+        return meta
+
+    def to_yaml_tree(self, meta, tag, ctx):
+        node = {}
+        node["meta"] = dict(meta)
+        node["key_comments"] = meta.key_comments
+        node["axes"] = meta.axes
+        node["data_shape"] = meta.data_shape
+        node["original_meta"] = meta._original_meta  # not the MappingProxy object
+        return node

ndcube/asdf/entry_points.py

@@ -37,6 +37,7 @@ def get_extensions():
     from ndcube.asdf.converters.ndcollection_converter import NDCollectionConverter
     from ndcube.asdf.converters.ndcube_converter import NDCubeConverter
     from ndcube.asdf.converters.ndcubesequence_converter import NDCubeSequenceConverter
+    from ndcube.asdf.converters.ndmeta_converter import NDMetaConverter
     from ndcube.asdf.converters.reorderedwcs_converter import ReorderedConverter
     from ndcube.asdf.converters.resampled_converter import ResampledConverter
     from ndcube.asdf.converters.tablecoord_converter import (
@@ -58,6 +59,7 @@ def get_extensions():
         CompoundConverter(),
         NDCubeSequenceConverter(),
         NDCollectionConverter(),
+        NDMetaConverter(),
         ]
     _manifest_uri = "asdf://sunpy.org/ndcube/manifests/ndcube-1.0.0"
 

ndcube/asdf/resources/manifests/ndcube-1.0.0.yaml

@@ -41,3 +41,6 @@ tags:
 
   - tag_uri:  "tag:sunpy.org:ndcube/ndcube/ndcollection-1.0.0"
     schema_uri: "asdf://sunpy.org/ndcube/schemas/ndcollection-1.0.0"
+
+  - tag_uri:  "tag:sunpy.org:ndcube/meta/ndmeta-1.0.0"
+    schema_uri: "asdf://sunpy.org/ndcube/schemas/ndmeta-1.0.0"

ndcube/asdf/resources/schemas/ndcube-1.0.0.yaml

@@ -1,7 +1,7 @@
 %YAML 1.1
 ---
 $schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
-id: "asdf://sunpy.org/ndcube/schemas/NDCube-1.0.0"
+id: "asdf://sunpy.org/ndcube/schemas/ndcube-1.0.0"
 
 title:
   Represents the ndcube NDCube object

ndcube/asdf/resources/schemas/ndmeta-1.0.0.yaml

@@ -0,0 +1,27 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "asdf://sunpy.org/ndcube/schemas/ndmeta-1.0.0"
+
+title:
+  Represents the ndcube NDMeta object
+
+description:
+  Represents the ndcube NDMeta object
+
+type: object
+properties:
+  meta:
+    type: object
+  key_comments:
+    type: object
+  axes:
+    type: object
+  data_shape:
+    tag: "tag:stsci.edu:asdf/core/ndarray-1.*"
+  original_meta:
+    type: object
+
+required: [meta, key_comments, axes, data_shape, original_meta]
+additionalProperties: true
+...

ndcube/meta.py

@@ -184,11 +184,11 @@ def _sanitize_axis_value(self, axis, value, key):
         if isinstance(axis, numbers.Integral):
             axis = (axis,)
         if len(axis) == 0:
-            return ValueError(axis_err_msg)
+            raise ValueError(axis_err_msg)
         # Verify each entry in axes is an iterable of ints or a scalar.
         if not (isinstance(axis, collections.abc.Iterable)
                 and all(isinstance(i, numbers.Integral) for i in axis)):
-            return ValueError(axis_err_msg)
+            raise ValueError(axis_err_msg)
         # If metadata's axis/axes include axis beyond current data shape, extend it.
         data_shape = self.data_shape
         if max(axis) >= len(data_shape):

ndcube/tests/helpers.py

@@ -107,10 +107,12 @@ def assert_metas_equal(test_input, expected_output):
         else:
             assert np.allclose(test_input.data_shape, expected_output.data_shape)
 
-        for test_value, expected_value in zip(test_input.values(), expected_output.values()):
+        for key in test_input.keys():
+            test_value = test_input[key]
+            expected_value = expected_output[key]
             try:
                 assert test_value == expected_value
-            except ValueError as err:  # noqa: PERF203
+            except ValueError as err:
                 if multi_element_msg in err.args[0]:
                     assert np.allclose(test_value, expected_value)
         for key in test_input.axes.keys():