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 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
docs: Returns
  		-------
  		PriorFactory