code: def segment_to_vector(self, seg):
          
          ft_dict = {ft: val for (val, ft) in self.fts(seg)}
          return [ft_dict[name] for name in self.names]
docs: Given a Unicode IPA segment, return a list of feature specificiations
          in cannonical order.
  
          Args:
              seg (unicode): IPA consonant or vowel
  
          Returns:
              list: feature specifications ('+'/'-'/'0') in the order from
              `FeatureTable.names`