docs: def z2h(text, ignore='', kana=True, ascii=False, digit=False):
      """Convert Full-width (Zenkaku) Katakana to Half-width (Hankaku) Katakana
  
      Parameters
      ----------
      text : str
          Full-width Katakana string.
      ignore : str
          Characters to be ignored in converting.
      kana : bool
          Either converting Kana or not.
      ascii : bool
          Either converting ascii or not.
      digit : bool
          Either converting digit or not.
  
      Return
      ------
      str
          Half-width Katakana string.
  
      Examples
      --------
      >>> print(jaconv.z2h('ティロフィナーレ'))
      ﾃｨﾛﾌｨﾅｰﾚ
      >>> print(jaconv.z2h('ティロフィナーレ', ignore='ィ'))
      ﾃィﾛﾌィﾅｰﾚ
      >>> print(jaconv.z2h('ＡＢＣＤ', ascii=True))
      abcd
      >>> print(jaconv.z2h('１２３４', digit=True))
      1234
      """
      if ascii:
          if digit:
              if kana:
                  z2h_map = Z2H_ALL
              else:
                  z2h_map = Z2H_AD
          elif kana:
              z2h_map = Z2H_AK
          else:
              z2h_map = Z2H_A
      elif digit:
          if kana:
              z2h_map = Z2H_DK
          else:
              z2h_map = Z2H_D
      else:
          z2h_map = Z2H_K
      if ignore:
          z2h_map = _exclude_ignorechar(ignore, z2h_map.copy())
      return _convert(text, z2h_map)