docs: def convtable2dict(convtable, locale, update=None):
      """
      Convert a list of conversion dict to a dict for a certain locale.
  
      >>> sorted(convtable2dict([{'zh-hk': '列斯', 'zh-hans': '利兹', 'zh': '利兹', 'zh-tw': '里茲'}, {':uni': '巨集', 'zh-cn': '宏'}], 'zh-cn').items())
      [('列斯', '利兹'), ('利兹', '利兹'), ('巨集', '宏'), ('里茲', '利兹')]
      """
      rdict = update.copy() if update else {}
      for r in convtable:
          if ':uni' in r:
              if locale in r:
                  rdict[r[':uni']] = r[locale]
          elif locale[:-1] == 'zh-han':
              if locale in r:
                  for word in r.values():
                      rdict[word] = r[locale]
          else:
              v = fallback(locale, r)
              for word in r.values():
                  rdict[word] = v
      return rdict