code: def search(self, ngram):
          '''
          Parameters
          ----------
          ngram, str or unicode, string to search for
  
          Returns
          -------
          pd.DataFrame, {self._parsed_col: <matching texts>, self._category_col: <corresponding categories>, ...}
  
          '''
          mask = self._document_index_mask(ngram)
          return self._df[maskf search(self, ngram):
          '''
          Parameters
          ----------
          ngram, str or unicode, string to search for
  
          Returns
          -------
          pd.DataFrame, {self._parsed_col: <matching texts>, self._category_col: <corresponding categories>, ...}
  
          '''
          mask = self._document_index_mask(ngram)
          return self._df[mask]
docs: Parameters
          ----------
          ngram, str or unicode, string to search for
  
          Returns
          -------
          pd.DataFrame, {self._parsed_col: <matching texts>, self._category_col: <corresponding categories>, ...}