Implement bind_namespaces strategy for Prefix.cc

examples/bind_prefix_cc.py

@@ -0,0 +1,18 @@
+"""
+Prefix.cc is a community curated prefix map. By using `bind_namespace="cc"`,
+you can set a namespace manager or graph to dynamically load prefixes from
+this resource.
+"""
+
+import rdflib
+
+graph = rdflib.Graph(bind_namespaces="cc")
+
+# The Gene Ontology is a biomedical ontology describing
+# biological processes, cellular locations, and cellular components.
+# It is typically abbreviated with the prefix "go" and uses PURLs
+# issued by the Open Biological and Biomedical Ontologies Foundry.
+prefix_map = {prefix: str(ns) for prefix, ns in graph.namespaces()}
+assert "go" in prefix_map
+assert prefix_map["go"] == "http://purl.obolibrary.org/obo/GO_"
+assert graph.qname("http://purl.obolibrary.org/obo/GO_0032571") == "go:0032571"

rdflib/_type_checking.py

@@ -27,5 +27,5 @@
 else:
     from typing_extensions import Literal as PyLiteral
 
-_NamespaceSetString = PyLiteral["core", "rdflib", "none"]
+_NamespaceSetString = PyLiteral["core", "rdflib", "none", "cc"]
 _MulPathMod = PyLiteral["*", "+", "?"]  # noqa: F722

rdflib/namespace/__init__.py

@@ -7,6 +7,7 @@
 from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Set, Tuple, Union
 from unicodedata import category
 from urllib.parse import urldefrag, urljoin
+from urllib.request import urlopen
 
 from rdflib.term import URIRef, Variable, _is_valid_uri
 
@@ -372,7 +373,6 @@ class NamespaceManager(object):
         * note this is NOT default behaviour
     * cc:
         * using prefix bindings from prefix.cc which is a online prefixes database
-        * not implemented yet - this is aspirational
 
     .. attention::
 
@@ -427,11 +427,14 @@ def __init__(
             for prefix, ns in _NAMESPACE_PREFIXES_CORE.items():
                 self.bind(prefix, ns)
         elif bind_namespaces == "cc":
+            for prefix, ns in _NAMESPACE_PREFIXES_RDFLIB.items():
+                self.bind(prefix, ns)
+            for prefix, ns in _NAMESPACE_PREFIXES_CORE.items():
+                self.bind(prefix, ns)
             # bind any prefix that can be found with lookups to prefix.cc
-            # first bind core and rdflib ones
-            # work out remainder - namespaces without prefixes
-            # only look those ones up
-            raise NotImplementedError("Haven't got to this option yet")
+            for prefix, ns in _get_prefix_cc().items():
+                # note that prefixes are lowercase-only in prefix.cc
+                self.bind(prefix, ns)
         elif bind_namespaces == "core":
             # bind a few core RDF namespaces - default
             for prefix, ns in _NAMESPACE_PREFIXES_CORE.items():
@@ -728,6 +731,13 @@ def absolutize(self, uri: str, defrag: int = 1) -> URIRef:
         return URIRef(result)
 
 
+def _get_prefix_cc():
+    """Get the context from Prefix.cc."""
+    response = urlopen("https://prefix.cc/context.jsonld")
+    context = json.loads(response.read())
+    return context["@context"]
+
+
 # From: http://www.w3.org/TR/REC-xml#NT-CombiningChar
 #
 # * Name start characters must have one of the categories Ll, Lu, Lo,

test/test_namespace/test_namespacemanager.py

@@ -181,6 +181,22 @@ def test_graph_bind_namespaces(
         assert namespaces is None
 
 
+def test_graph_bind_cc():
+    """Test binding Prefix.cc.
+
+    Note that since prefix.cc is an inherently dynamic resource,
+    that checking an exact equivalence is not applicable.
+    """
+    graph = Graph(bind_namespaces="cc")
+    namespaces = {*graph.namespaces()}
+    for namespaces in [
+        _NAMESPACE_PREFIXES_CORE,
+        _NAMESPACE_PREFIXES_RDFLIB,
+        {"go", "atcc"},  # represent some prefixes in Prefix.cc
+    ]:
+        assert all(ns in namespaces for ns in _NAMESPACE_PREFIXES_CORE)
+
+
 @pytest.mark.parametrize(
     ["selector", "expected_result"],
     [