Refactor: generalize relations and add SKOS.narrower

- Generalized "broader", "related" and "mappings" as "relations".
- [#31] Added mapping of 5XX $w=h to skos:narrower

README.rst

@@ -240,9 +240,9 @@ Mapping schema for MARC21 Authority
 
 Only a small part of the MARC21 Authority data model is converted.
 
-==========================================================  =====================================
+==========================================================  ===================================================================
 MARC21XML                                                    RDF
-==========================================================  =====================================
+==========================================================  ===================================================================
 ``001`` Control Number                                      ``dcterms:identifier``
 ``005`` Date and time of latest transaction                 ``dcterms:modified``
 ``008[0:6]`` Date entered on file                           ``dcterms:created``
@@ -251,7 +251,7 @@ MARC21XML                                                    RDF
 ``083`` Dewey Decimal Classification Number                 ``skos:exactMatch``  (see below)
 ``1XX`` Headings                                            ``skos:prefLabel``
 ``4XX`` See From Tracings                                   ``skos:altLabel``
-``5XX`` See Also From Tracings                              ``skos:related`` or `skos:broader`` (see below)
+``5XX`` See Also From Tracings                              ``skos:related``, ``skos:broader`` or ``skos:narrower`` (see below)
 ``667`` Nonpublic General Note                              ``skos:editorialNote``
 ``670`` Source Data Found                                   ``skos:note``
 ``677`` Definition                                          ``skos:definition``
@@ -260,13 +260,15 @@ MARC21XML                                                    RDF
 ``681`` Subject Example Tracing Note                        ``skos:example``
 ``682`` Deleted Heading Information                         ``skos:changeNote``
 ``688`` Application History Note                            ``skos:historyNote``
-==========================================================  =====================================
+==========================================================  ===================================================================
 
 Notes:
 
 *  Mappings are generated for 065, 080 and 083 only if an URI pattern for the
    classification scheme has been defined in the config.
 
-* ``skos:related`` and ``skos:broader`` is currently only generated from 5XX fields
-  if the fields contain a ``$0`` subfield containing either the control number or the
-  URI of the related record.
+* SKOS relations are generated from 5XX fields if the fields contain a ``$0``
+  subfield containing either the control number or the URI of the related record.
+  The relationship type is ``skos:broader`` if ``$w=g``, ``skos:narrower`` if ``$w=h``,
+  and ``skos:related`` otherwise.
+  If  ``$w=r`` and ``$4`` contains an URI, that URI is used as the relationship type.

mc2skos/mc2skos.py

@@ -84,18 +84,10 @@ def add_record_to_graph(graph, record, options):
         for label in record.altLabel:
             graph.add((record_uri, SKOS.altLabel, Literal(label['term'], lang=record.lang)))
 
-    # Add skos:broader
-    for uri in record.broader:
-        graph.add((record_uri, SKOS.broader, URIRef(uri)))
-
-    # Add skos:related
-    for uri in record.related:
-        graph.add((record_uri, SKOS.related, URIRef(uri)))
-
-    # Add mappings
-    for mapping in record.mappings:
-        if mapping.get('uri') is not None:
-            graph.add((record_uri, mapping.get('relation'), URIRef(mapping['uri'])))
+    # Add relations (SKOS:broader, SKOS:narrower, SKOS:xxxMatch, etc.)
+    for relation in record.relations:
+        if relation.get('uri') is not None:
+            graph.add((record_uri, relation.get('relation'), URIRef(relation['uri'])))
 
     # Add notes
     if options.get('include_notes'):

mc2skos/record.py

@@ -50,6 +50,10 @@
 }
 
 
+def is_uri(value):
+    return value.startswith('http://') or value.startswith('https://')
+
+
 class InvalidRecordError(RuntimeError):
     pass
 
@@ -159,8 +163,6 @@ def __init__(self, record, options=None):
         self.control_number_identifier = None
         self.created = None
         self.modified = None
-        self.broader = []
-        self.related = []
         self.lang = None
         self.prefLabel = None
         self.altLabel = []
@@ -172,7 +174,7 @@ def __init__(self, record, options=None):
         self.historyNote = []
         self.changeNote = []
         self.example = []
-        self.mappings = []
+        self.relations = []
         self.webDeweyExtras = {}
         self.deprecated = False
         self.is_top_concept = False
@@ -288,7 +290,10 @@ def parse(self, options):
         if parent_notation is not None:
             parent_uri = self.scheme.get_uri(collection='class', object=parent_notation)
             if parent_uri is not None:
-                self.broader.append(parent_uri)
+                self.relations.append({
+                    'uri': parent_uri,
+                    'relation': SKOS.broader
+                })
 
         # 253 : Complex See Reference (R)
         # Example:
@@ -617,10 +622,10 @@ def append_class_uri(class_obj):
 
         return class_obj
 
-    def append_mapping(self, scheme, relation, **kwargs):
+    def append_relation(self, scheme, relation, **kwargs):
         uri = scheme.get_uri(**kwargs)
         if uri:
-            self.mappings.append({
+            self.relations.append({
                 'uri': uri,
                 'relation': relation,
             })
@@ -644,7 +649,7 @@ def parse(self, options):
         # 065: Other Classification Number
         el = self.record.first('mx:datafield[@tag="065"]')
         if el is not None:
-            self.append_mapping(
+            self.append_relation(
                 ConceptScheme(el.text('mx:subfield[@code="2"]'), ClassificationRecord),
                 SKOS.exactMatch,
                 object=self.get_class_number(el)
@@ -653,7 +658,7 @@ def parse(self, options):
         # 080: Universal Decimal Classification Number
         el = self.record.first('mx:datafield[@tag="080"]')
         if el is not None:
-            self.append_mapping(
+            self.append_relation(
                 ConceptScheme('udc', ClassificationRecord),
                 SKOS.exactMatch,
                 object=self.get_class_number(el)
@@ -662,7 +667,7 @@ def parse(self, options):
         # 083: Dewey Decimal Classification Number
         el = self.record.first('mx:datafield[@tag="083"]')
         if el is not None:
-            self.append_mapping(
+            self.append_relation(
                 ConceptScheme('ddc', ClassificationRecord, edition=el.text('mx:subfield[@code="2"]')),
                 SKOS.exactMatch,
                 object=self.get_class_number(el)
@@ -682,18 +687,30 @@ def parse(self, options):
         for heading in self.get_terms('5'):
             local_id = heading['node'].text('mx:subfield[@code="0"]')
             if local_id:
-                m = re.match('^\(.+\)(.+)$', local_id)
-                if m:
-                    local_id = m.group(1)
-                if local_id.startswith('http'):
-                    uri = local_id
-                else:
-                    uri = self.scheme.get_uri(control_number=local_id)
                 if local_id:
-                    if heading['node'].text('mx:subfield[@code="w"]') == 'g':
-                        self.broader.append(uri)
+                    sf_w = heading['node'].text('mx:subfield[@code="w"]')
+                    sf_4 = heading['node'].text('mx:subfield[@code="4"]')
+
+                    if sf_w == 'g':
+                        relation = SKOS.broader
+                    elif sf_w == 'h':
+                        relation = SKOS.narrower
+                    elif sf_w == 'r' and is_uri(sf_4):
+                        relation = sf_4
+                    else:
+                        relation = SKOS.related
+
+                    if is_uri(local_id):
+                        self.relations.append({
+                            'uri': uri,
+                            'relation': relation,
+                        })
                     else:
-                        self.related.append(uri)
+                        self.append_relation(
+                            self.scheme,
+                            relation,
+                            control_number=local_id
+                        )
 
         # 667 : Nonpublic General Note
         # madsrdf:editorialNote

tests/test_process_record.py

@@ -58,8 +58,9 @@ def testAddTableNumber(self):
         assert rec.display is True
         assert rec.synthesized is False
         assert rec.notation == '811-818:2;4'
-        assert len(rec.broader) == 1
-        assert rec.broader[0] == 'http://dewey.info/class/811-818/e23/'
+        assert len(rec.relations) == 1
+        assert rec.relations[0]['uri'] == 'http://dewey.info/class/811-818/e23/'
+        assert rec.relations[0]['relation'] == SKOS.broader
 
     def testHistoricalAddTableNumber(self):
         rec = ClassificationRecord('''