docstr: Returns
  -------
  PriorFactory
docstr_tok: ["Returns","--","--","--","-","PriorFactory"]
code: def drop_zero_priors(self):
      """
      Returns
      -------
      PriorFactory
      """
      self.term_doc_mat = self.term_doc_mat.remove_terms(
          self.priors[self.priors == 0].index
      )
      self._reindex_priors()
      return self
  
imports: import pandas
  import numpy
  from scattertext.termranking import AbsoluteFrequencyRanker
  from scattertext.termsignificance.LogOddsRatioInformativeDirichletPiror import LogOddsRatioInformativeDirichletPrior
label_desc: Use image node_id 13 for calling the PriorFactory obj's underlying member method code with example usage: obj.drop_zero_priors() and returns: self