def evalDeleteData(ctx, u):
    # remove triples
    g = ctx.graph
    g -= u.triples

    # remove quads
    # u.quads is a dict of graphURI=>[triples]
    for g in u.quads:
        cg = ctx.dataset.get_context(g)
        cg -= u.quads[g]
Change the messages that correspond to certain keys.
dataset/ETHPy150Open RDFLib/rdflib/rdflib/plugins/sparql/update.py/evalDeleteData--crossover with--dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/Mailbox.update