gremlin python retrieve ids and labels (valueMap(True))

My guess is that you are running into trouble with this recently reported bug with valueMap(true):

https://issues.apache.org/jira/browse/TINKERPOP-1860

it is patched and will be fixed with release of 3.3.2. Until then you will have to work around the issue as there really is no fix short of reverting to GraphSON 2.0 (which comes with it's own set of downsides). One workaround would be to project() your results:

gremlin> g.V().project('props','id','label').
......1>         by(valueMap()).
......2>         by(id).
......3>         by(label)
==>[props:[name:[marko],age:[29]],id:1,label:person]
==>[props:[name:[vadas],age:[27]],id:2,label:person]
==>[props:[name:[lop],lang:[java]],id:3,label:software]
==>[props:[name:[josh],age:[32]],id:4,label:person]
==>[props:[name:[ripple],lang:[java]],id:5,label:software]
==>[props:[name:[peter],age:[35]],id:6,label:person]