an additional extension of RDF semantics for formulae. For the academically inclined, Graham Klyne's 'formal' extension (see external links) is probably a good read. Formulae are represented formally by the 'QuotedGraph' class and disjoint from regular RDF graphs in that their statements are quoted. Persistence RDFLib provides an abstracted Store API for persistence of RDF and Notation 3. The Graph class works with instances of this API (as the first argument to its constructor) for triple-based management of an RDF store including: garbage collection, transaction management, update, pattern matching, removal, length, and database management () . Additional persistence mechanisms can be supported by implementing this API for a different store. Currently supported databases: HDT MySQL SQLite Berkeley DB Zope Object Database Random-access memory Redland RDF Application Framework Store instances can be created with the plugin function: from rdflib import plugin from rdflib.store import Store plugin.get('.. one of the supported Stores ..', Store)(identifier=.. id of conjunctive graph ..) 'Higher-order' idioms There are a few high-level APIs that extend RDFLib graphs into other Pythonic idioms. For more a more explicit Python binding, there are Sparta, SuRF & FunOWL. References External links Python (programming language) libraries RDF data access Resource Description Framework