Formatted Code, Codelist, Concepts and ConceptScheme.

src/pysdmx/model/__base.py

@@ -18,6 +18,7 @@ class Annotation(Struct, frozen=True, omit_defaults=True):
         url: The URL of the annotation.
         type: The type of the annotation.
     """
+
     id: Optional[str] = None
     title: Optional[str] = None
     text: Optional[str] = None
@@ -67,6 +68,7 @@ class IdentifiableArtefact(AnnotableArtefact):
         uri: The URI of the artefact.
         urn: The URN of the artefact.
     """
+
     id: str
     uri: Optional[str] = None
     urn: Optional[str] = None
@@ -86,6 +88,7 @@ class NameableArtefact(IdentifiableArtefact):
         name: The name of the artefact.
         description: The description of the artefact.
     """
+
     name: Optional[str] = None
     description: Optional[str] = None
 
@@ -99,6 +102,7 @@ class VersionableArtefact(NameableArtefact):
         valid_from: The date from which the artefact is valid.
         valid_to: The date to which the artefact is valid.
     """
+
     version: str = "1.0"
     valid_from: Optional[datetime] = None
     valid_to: Optional[datetime] = None
@@ -116,6 +120,7 @@ class MaintainableArtefact(VersionableArtefact):
         structure_url: The URL of the structure.
         maintainer: The maintainer of the artefact.
     """
+
     is_final: bool = False
     is_external_reference: bool = False
     service_url: str = None
@@ -138,6 +143,7 @@ class Agency(MaintainableArtefact):
     Attributes:
         contacts: The contact of the agency.
     """
+
     contacts = Sequence["Contact"]
 
 
@@ -151,6 +157,7 @@ class Item(NameableArtefact):
         parent: The parent of the item.
         children: The children of the item.
     """
+
     scheme: "ItemScheme" = None
     parent: Optional["Item"] = None
     children: Sequence["Item"] = ()
@@ -165,9 +172,22 @@ class ItemScheme(MaintainableArtefact):
         items: The list of items in the scheme.
         is_partial: Whether the scheme is partial.
     """
+
     items: Sequence["Item"] = ()
     is_partial: bool = False
 
     def __iter__(self) -> Iterator[Item]:
         """Return an iterator over the list of items."""
         yield from self.items
+
+    def __len__(self) -> int:
+        """Return the number of codes in the codelist."""
+        return len(self.items)
+
+    def __getitem__(self, id_: str) -> Optional[Item]:
+        """Return the code identified by the supplied ID."""
+        out = list(filter(lambda item: item.id == id_, self.items))
+        if len(out) == 0:
+            return None
+        else:
+            return out[0]

src/pysdmx/model/code.py

@@ -21,6 +21,8 @@
 
 from msgspec import Struct
 
+from pysdmx.model.__base import ItemScheme
+
 
 class Code(Struct, frozen=True, omit_defaults=True):
     """A code, such as a country code in the list of ISO 3166 codes.
@@ -49,7 +51,7 @@ def __str__(self) -> str:
         return out
 
 
-class Codelist(Struct, frozen=True, omit_defaults=True):
+class Codelist(ItemScheme):
     """An immutable collection of codes, such as the ISO 3166 country codes.
 
     A codelist is **maintained by its agency**, typically, an organisation
@@ -75,30 +77,9 @@ class Codelist(Struct, frozen=True, omit_defaults=True):
         codes: The list of codes in the codelist.
     """
 
-    id: str
-    name: str
-    agency: str
-    description: Optional[str] = None
-    version: str = "1.0"
-    codes: Sequence[Code] = ()
+    items: Sequence[Code] = ()
     sdmx_type: Literal["codelist", "valuelist"] = "codelist"
 
-    def __iter__(self) -> Iterator[Code]:
-        """Return an iterator over the list of codes."""
-        yield from self.codes
-
-    def __len__(self) -> int:
-        """Return the number of codes in the codelist."""
-        return len(self.codes)
-
-    def __getitem__(self, id_: str) -> Optional[Code]:
-        """Return the code identified by the supplied ID."""
-        out = list(filter(lambda code: code.id == id_, self.codes))
-        if len(out) == 0:
-            return None
-        else:
-            return out[0]
-
 
 class HierarchicalCode(Struct, frozen=True, omit_defaults=True):
     """A code, as used in a hierarchy.

src/pysdmx/model/concept.py

@@ -16,6 +16,7 @@
 
 from msgspec import Struct
 
+from pysdmx.model.__base import Item, ItemScheme
 from pysdmx.model.code import Codelist
 
 
@@ -114,7 +115,7 @@ def __str__(self) -> str:
         return ", ".join(out)
 
 
-class Concept(Struct, frozen=True, omit_defaults=True):
+class Concept(Item):
     """A concept (aka **variable**), such as frequency, reference area, etc.
 
     Concepts are used to **describe the relevant characteristics** of a
@@ -144,11 +145,8 @@ class Concept(Struct, frozen=True, omit_defaults=True):
             which the codes are taken.
     """
 
-    id: str
     dtype: DataType = DataType.STRING
     facets: Optional[Facets] = None
-    name: Optional[str] = None
-    description: Optional[str] = None
     codes: Optional[Codelist] = None
     enum_ref: Optional[str] = None
 
@@ -162,7 +160,7 @@ def __str__(self) -> str:
         return ", ".join(out)
 
 
-class ConceptScheme(Struct, frozen=True, omit_defaults=True):
+class ConceptScheme(ItemScheme):
     """An immutable collection of concepts.
 
     A concept scheme is **maintained by its agency**, typically, an
@@ -181,28 +179,7 @@ class ConceptScheme(Struct, frozen=True, omit_defaults=True):
         description: Additional descriptive information about the scheme
             (e.g. "The set of concepts in the SDMX Glossary").
         version: The scheme version (e.g. 2.0)
-        concepts: The list of concepts in the scheme.
+        items: The list of concepts in the scheme.
     """
 
-    id: str
-    name: str
-    agency: str
-    description: Optional[str] = None
-    version: str = "1.0"
-    concepts: Sequence[Concept] = ()
-
-    def __iter__(self) -> Iterator[Concept]:
-        """Return an iterator over the list of concepts."""
-        yield from self.concepts
-
-    def __len__(self) -> int:
-        """Return the number of concepts in the concept scheme."""
-        return len(self.concepts)
-
-    def __getitem__(self, id_: str) -> Optional[Concept]:
-        """Return the concept identified by the given ID."""
-        out = list(filter(lambda concept: concept.id == id_, self.concepts))
-        if len(out) == 0:
-            return None
-        else:
-            return out[0]
+    items: Sequence[Concept] = ()