RDFLib is a pure Python package work working with RDF. RDFLib contains most things you need to work with RDF, including:
If you never used RDFLib, click through these
If you already worked with RDF and need to know the peculiarities of RDFLib, these are for you.
The nitty-gritty details of everything.
A functional property is a property that can have only one (unique) value y for each instance x, i.e. there cannot be two distinct values y1 and y2 such that the pairs (x,y1) and (x,y2) are both instances of this
A property is transitive:
if whenever an element a is related to an element b, and b is in turn related to an element c, then a is also related to c. – http://en.wikipedia.org/wiki/Transitive_relation
Standard examples include rdfs:subClassOf or greater-than