title: Gremlin python - how to ignore property of type List when adding properties to vertex
body: <p>I want to add persons as vertices in a graph which works with the following code:</p>
  <pre><code>from gremlin_python.process.graph_traversal import __
  from gremlin_python.process.traversal import Column
  
  persons = [{&quot;id&quot;:1,&quot;name&quot;:&quot;bob&quot;,&quot;age&quot;:25}, {&quot;id&quot;:2,&quot;name&quot;:&quot;joe&quot;,&quot;age&quot;:25,&quot;occupation&quot;:&quot;lawyer&quot;}]    
  
  g.inject(persons).unfold().as_('entity').\
      addV('entity').as_('v').\
          sideEffect(__.select('entity').unfold().as_('kv').select('v').\
                     property(__.select('kv').by(Column.keys),
                              __.select('kv').by(Column.values)
                              )
                    ).iterate()
  </code></pre>
  <p><strong>Question 1:</strong>
  What if one of the properties is a List or dict. Example:</p>
  <pre><code>persons = [{&quot;id&quot;:1,&quot;name&quot;:&quot;bob&quot;,&quot;age&quot;:25, &quot;house&quot;:{&quot;a&quot;:1,&quot;b&quot;:4}}, {&quot;id&quot;:2,&quot;name&quot;:&quot;joe&quot;,&quot;age&quot;:25,&quot;occupation&quot;:&quot;lawyer&quot;,&quot;house&quot;:{&quot;a&quot;:1,&quot;b&quot;:4}}]
  </code></pre>
  <p>How do I ignore that 1 property (house) but still add the rest to the person vertex? Then take house and create another vertex (add properties a and b) with edge to person?</p>
  <p><strong>Question 2:</strong>
  What if I want to modify an attribute before I add it as a property to the graph?
  For example: Convert id into string and then add it as property</p>