skip prefix generation for predicates corresponding to base namespace

Author: bulricht

rdflib/plugins/serializers/turtle.py

@@ -264,6 +264,9 @@ def preprocessTriple(self, triple: _TripleType) -> None:
  if i == VERB and node in self.keywords:
  # predicate is a keyword
  continue
+ if i == VERB and node.startswith(self.store.base):
+ # predicate corresponds to base namespace
+ continue
  # Don't use generated prefixes for subjects and objects
  self.getQName(node, gen_prefix=(i == VERB))
  if isinstance(node, Literal) and node.datatype: