otsrdflib 0.2.0

Ordered Turtle Serializer for rdflib

An extension to the rdflib Turtle serializer that adds order (at the price of speed). Useful when you need to generate diffs between Turtle files, or just to make it easier for human beings to inspect the files.

$ pip install otsrdflib

Usage:

from rdflib import graph
from otsrdflib import OrderedTurtleSerializer

my_graph = Graph()

out = open('out.ttl', 'wb')
serializer = OrderedTurtleSerializer(my_graph)
serializer.serialize(out)

Class order is imposed by setting serializer.topClasses. The default list is suitable for thesauri and other controlled vocabularies:

serializer.topClasses = [SKOS.ConceptScheme,
                       FOAF.Organization,
                       SD.Service,
                       SD.Dataset,
                       SD.Graph,
                       SD.NamedGraph,
                       ISOTHES.ThesaurusArray,
                       SKOS.Concept]

Instance order (within a class) is imposed by adding URI patterns to serializer.sorters:

serializer.sorters = {
  'http://dewey.info/class/(T?([0-9]+)\-\-)?([0-9.]+)': lambda x: (0 if x[1] is None else int(x[1])*1000) + float(x[2])
}

URIs that doesn’t match any of the specialized sorters are sorted alphabetically using the Python cmp method.