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Diffstat (limited to 'creactistore/_templates/lib/rdflib/collection.py')
| -rw-r--r-- | creactistore/_templates/lib/rdflib/collection.py | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/creactistore/_templates/lib/rdflib/collection.py b/creactistore/_templates/lib/rdflib/collection.py new file mode 100644 index 0000000..6b61dd8 --- /dev/null +++ b/creactistore/_templates/lib/rdflib/collection.py @@ -0,0 +1,262 @@ +from rdflib.namespace import RDF +from rdflib.term import BNode +from rdflib.term import Literal +from rdflib.graph import Graph +from rdflib.py3compat import format_doctest_out + +__all__ = ['Collection'] + +class Collection(object): + __doc__ = format_doctest_out(""" + See 3.3.5 Emulating container types: http://docs.python.org/ref/sequence-types.html#l2h-232 + + >>> from rdflib.graph import Graph + >>> listName = BNode() + >>> g = Graph('IOMemory') + >>> listItem1 = BNode() + >>> listItem2 = BNode() + >>> g.add((listName,RDF.first,Literal(1))) + >>> g.add((listName,RDF.rest,listItem1)) + >>> g.add((listItem1,RDF.first,Literal(2))) + >>> g.add((listItem1,RDF.rest,listItem2)) + >>> g.add((listItem2,RDF.rest,RDF.nil)) + >>> g.add((listItem2,RDF.first,Literal(3))) + >>> c=Collection(g,listName) + >>> print(list(c)) + [rdflib.term.Literal(%(u)s'1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer')), rdflib.term.Literal(%(u)s'2', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer')), rdflib.term.Literal(%(u)s'3', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))] + >>> 1 in c + True + >>> len(c) + 3 + >>> c._get_container(1) == listItem1 + True + >>> c.index(Literal(2)) == 1 + True + """) + def __init__(self, graph, uri, seq=[]): + self.graph = graph + self.uri = uri or BNode() + for item in seq: + self.append(item) + + def n3(self): + """ + >>> from rdflib.graph import Graph + >>> listName = BNode() + >>> g = Graph('IOMemory') + >>> listItem1 = BNode() + >>> listItem2 = BNode() + >>> g.add((listName,RDF.first,Literal(1))) + >>> g.add((listName,RDF.rest,listItem1)) + >>> g.add((listItem1,RDF.first,Literal(2))) + >>> g.add((listItem1,RDF.rest,listItem2)) + >>> g.add((listItem2,RDF.rest,RDF.nil)) + >>> g.add((listItem2,RDF.first,Literal(3))) + >>> c=Collection(g,listName) + >>> print(c.n3()) + ( "1"^^<http://www.w3.org/2001/XMLSchema#integer> "2"^^<http://www.w3.org/2001/XMLSchema#integer> "3"^^<http://www.w3.org/2001/XMLSchema#integer> ) + """ + return "( %s )"%(' '.join([i.n3() for i in self])) + + def _get_container(self, index): + """Gets the first, rest holding node at index.""" + assert isinstance(index, int) + graph = self.graph + container = self.uri + i = 0 + while i<index: + i += 1 + container = graph.value(container, RDF.rest) + if container is None: + break + return container + + def __len__(self): + """length of items in collection.""" + count = 0 + links=set() + for item in self.graph.items(self.uri): + assert item not in links,"There is a loop in the RDF list! (%s has been processed before)"%item + links.add(item) + count += 1 + return count + + def index(self, item): + """ + Returns the 0-based numerical index of the item in the list + """ + listName = self.uri + index = 0 + while True: + if (listName,RDF.first,item) in self.graph: + return index + else: + newLink = list(self.graph.objects(listName,RDF.rest)) + index += 1 + if newLink == [RDF.nil]: + raise ValueError("%s is not in %s"%(item,self.uri)) + elif not newLink: + raise Exception("Malformed RDF Collection: %s"%self.uri) + else: + assert len(newLink)==1, "Malformed RDF Collection: %s"%self.uri + listName = newLink[0] + + def __getitem__(self, key): + """TODO""" + c = self._get_container(key) + if c: + v = self.graph.value(c, RDF.first) + if v: + return v + else: + raise KeyError, key + else: + raise IndexError, key + + def __setitem__(self, key, value): + """TODO""" + c = self._get_container(key) + if c: + self.graph.add((c, RDF.first, value)) + else: + raise IndexError, key + + + def __delitem__(self, key): + """ + >>> from rdflib.namespace import RDF, RDFS + >>> from rdflib import Graph + >>> from pprint import pformat + >>> g=Graph() + >>> a=BNode('foo') + >>> b=BNode('bar') + >>> c=BNode('baz') + >>> g.add((a,RDF.first,RDF.type)) + >>> g.add((a,RDF.rest,b)) + >>> g.add((b,RDF.first,RDFS.label)) + >>> g.add((b,RDF.rest,c)) + >>> g.add((c,RDF.first,RDFS.comment)) + >>> g.add((c,RDF.rest,RDF.nil)) + >>> len(g) + 6 + >>> def listAncestry(node,graph): + ... for i in graph.subjects(RDF.rest,node): + ... yield i + >>> [str(node.n3()) for node in g.transitiveClosure(listAncestry,RDF.nil)] + ['_:baz', '_:bar', '_:foo'] + >>> lst=Collection(g,a) + >>> len(lst) + 3 + >>> b==lst._get_container(1) + True + >>> c==lst._get_container(2) + True + >>> del lst[1] + >>> len(lst) + 2 + >>> len(g) + 4 + + """ + self[key] # to raise any potential key exceptions + graph = self.graph + current = self._get_container(key) + assert current + if len(self)==1 and key>0: + pass + elif key==len(self)-1: + #the tail + priorLink = self._get_container(key-1) + self.graph.set((priorLink,RDF.rest,RDF.nil)) + graph.remove((current, None, None)) + else: + next = self._get_container(key+1) + prior = self._get_container(key-1) + assert next and prior + graph.remove((current, None, None)) + graph.set((prior, RDF.rest, next)) + + def __iter__(self): + """Iterator over items in Collections""" + return self.graph.items(self.uri) + + def append(self, item): + """ + >>> from rdflib.graph import Graph + >>> listName = BNode() + >>> g = Graph() + >>> c=Collection(g,listName,[Literal(1),Literal(2)]) + >>> links = [list(g.subjects(object=i,predicate=RDF.first))[0] for i in c] + >>> len([i for i in links if (i,RDF.rest,RDF.nil) in g]) + 1 + + """ + container = self.uri + graph = self.graph + #iterate to the end of the linked list + rest = graph.value(container, RDF.rest) + while rest: + if rest == RDF.nil: + #the end, append to the end of the linked list + node = BNode() + graph.set((container, RDF.rest, node)) + container=node + break + else: + #move down one link + if container != self.uri: + rest = graph.value(rest, RDF.rest) + if not rest == RDF.nil: + container=rest + graph.add((container, RDF.first, item)) + graph.add((container, RDF.rest, RDF.nil)) + + def clear(self): + container = self.uri + graph = self.graph + while container: + rest = graph.value(container, RDF.rest) + graph.remove((container, RDF.first, None)) + graph.remove((container, RDF.rest, None)) + container = rest +def test(): + import doctest + doctest.testmod() + +if __name__=="__main__": + test() + + g = Graph() + + c = Collection(g, BNode()) + + assert len(c)==0 + + c = Collection(g, BNode(), [Literal("1"), Literal("2"), Literal("3"), Literal("4")]) + + assert len(c)==4 + + assert c[1]==Literal("2"), c[1] + + del c[1] + + assert list(c)==[Literal("1"), Literal("3"), Literal("4")], list(c) + + try: + del c[500] + except IndexError, i: + pass + + c.append(Literal("5")) + + print(list(c)) + + for i in c: + print(i) + + del c[3] + + c.clear() + + assert len(c)==0 + |