title: MXNet - what is python equivalent of getting scala's mxnet networkExecutor.gradDict("data")
body: <p>Trying to understand some Scala's code on network training in MXNet.</p>
  
  <p>I believe you can access gradient on the executor in Scala by calling <code>networkExecutor.gradDict("data")</code>, what would be equivalent of it in Python MXNet?</p>
  
  <p>Thanks! </p>