汉字转字母

#!/usr/bin/env python 
# -*- coding: utf-8 -*- 
def multi_get_letter(str_input): 
  if isinstance(str_input, unicode): 
    unicode_str = str_input 
  else: 
    try: 
      unicode_str = str_input.decode('utf8') 
    except: 
      try: 
        unicode_str = str_input.decode('gbk') 
      except: 
        print 'unknown coding'
        return
  return_list = [] 
  for one_unicode in unicode_str: 
    return_list.append(single_get_first(one_unicode)) 
  return return_list 
def single_get_first(unicode1): 
  str1 = unicode1.encode('gbk') 
  try:     
    ord(str1) 
    return str1 
  except: 
    asc = ord(str1[0]) * 256 + ord(str1[1]) - 65536
    if asc >= -20319 and asc <= -20284: 
      return 'a'
    if asc >= -20283 and asc <= -19776: 
      return 'b'
    if asc >= -19775 and asc <= -19219: 
      return 'c'
    if asc >= -19218 and asc <= -18711: 
      return 'd'
    if asc >= -18710 and asc <= -18527: 
      return 'e'
    if asc >= -18526 and asc <= -18240: 
      return 'f'
    if asc >= -18239 and asc <= -17923: 
      return 'g'
    if asc >= -17922 and asc <= -17418: 
      return 'h'
    if asc >= -17417 and asc <= -16475: 
      return 'j'
    if asc >= -16474 and asc <= -16213: 
      return 'k'
    if asc >= -16212 and asc <= -15641:    
    if asc >= -12556 and asc <= -11848: 
      return 'x'
    if asc >= -11847 and asc <= -11056: 
      return 'y'
    if asc >= -11055 and asc <= -10247: 
      return 'z'
    return '' 
def main(str_input): 
  a = multi_get_letter(str_input) 
  b = '' 
  for i in a: 
    b= b+i 
  print b 
if __name__ == "__main__":
  qwer=("上海","云南","内蒙古","北京","吉林","四川","天津","宁夏","安徽","山东","山西","广东","广西","新疆","江苏","江西","河北","河南","浙江","海南","湖北","湖南","甘肃","福建","西藏","贵州","辽宁","重庆","陕西","青海","黑龙江")  
  for i in qwer:

      main(i)

  str_input=u'欢迎你'
  main(str_input)