DO $$ plpy.notice("This is plpythonu.") $$ LANGUAGE plpythonu;
NOTICE:  This is plpythonu.
DO $$ plpy.notice("This is plpython2u.") $$ LANGUAGE plpython2u;
NOTICE:  This is plpython2u.
DO $$ raise Exception("error test") $$ LANGUAGE plpythonu;
ERROR:  Exception: error test
CONTEXT:  Traceback (most recent call last):
  PL/Python anonymous code block, line 1, in <module>
    raise Exception("error test") 
PL/Python anonymous code block