def val(x): v = value(x, e.expr, variables=True) if isinstance(v, Variable): return (0, v) elif isinstance(v, BNode): return (1, v) elif isinstance(v, URIRef): return (2, v) elif isinstance(v, Literal): return (3, v)
def _c(d): return [(k, value(ctx, v)) for k, v in d.iteritems() if v != 'UNDEF']
def val(x): try: return value(x, e.expr) except: return None