Question about Constituency Parser

Hi Folks:

I am still new to AllenNLP. I am using the constituency parser to develop algorithms for my voice application. I have questions about the constituency parser module, structured_prediction.

  1. Is there a way for me to do Predictor.from_path once? Can I cache the URI to

  2. I am having problems finding the documentation beyond the demo page.

  3. The demo mentions the Penn treebank. I thought this was a pre-trained model. Do I have to purchase Penn Treebank to get the same results.


  1. You can download that and give a local path, and things will work. You can also just keep the reference to the loaded predictor in your program, so you only have to load the predictor once, yes.
  2. See the guide.
  3. The pre-trained model does not require a license to the Penn Treebank. If you want to re-train it on that data, then you’ll need a license.