Python实现把数字转换成中文

#!/usr/bin/python
#-*- encoding: utf-8 -*-

import types

class NotIntegerError(Exception):
 pass

class OutOfRangeError(Exception):
 pass

_MAPPING = (u'零', u'一', u'二', u'三', u'四', u'五', u'六', u'七', u'八', u'九', )
_P0 = (u'', u'十', u'百', u'千', )
_S4, _S8, _S16 = 10 ** 4 , 10 ** 8, 10 ** 16
_MIN, _MAX = 0, 9999999999999999

def _to_chinese4(num):
 '''转换[0, 10000)之间的阿拉伯数字
 '''
 assert(0 <= num and num < _S4)
 if num < 10:
 return _MAPPING[num]
 else:
 lst = [ ]
 while num >= 10:
 lst.append(num % 10)
 num = num / 10
 lst.append(num)
 c = len(lst) # 位数
 result = u''
 
 for idx, val in enumerate(lst):
 if val != 0:
 result += _P0[idx] + _MAPPING[val]
 if idx < c - 1 and lst[idx + 1] == 0:
 result += u'零'
 
 return result[::-1].replace(u'一十', u'十')
 
def _to_chinese8(num):
 assert(num < _S8)
 to4 = _to_chinese4
 if num < _S4:
 return to4(num)
 else:
 mod = _S4
 high, low = num / mod, num % mod
 if low == 0:
 return to4(high) + u'万'
 else:
 if low < _S4 / 10:
 return to4(high) + u'万零' + to4(low)
 else:
 return to4(high) + u'万' + to4(low)
 
def _to_chinese16(num):
 assert(num < _S16)
 to8 = _to_chinese8
 mod = _S8
 high, low = num / mod, num % mod
 if low == 0:
 return to8(high) + u'亿'
 else:
 if low < _S8 / 10:
 return to8(high) + u'亿零' + to8(low)
 else:
 return to8(high) + u'亿' + to8(low)
 
def to_chinese(num):
 if type(num) != types.IntType and type(num) != types.LongType:
 raise NotIntegerError(u'%s is not a integer.' % num)
 if num < _MIN or num > _MAX:
 raise OutOfRangeError(u'%d out of range[%d, %d)' % (num, _MIN, _MAX))
 
 if num < _S4:
 return _to_chinese4(num)
 elif num < _S8:
 return _to_chinese8(num)
 else:
 return _to_chinese16(num)
 
if __name__ == '__main__':
 print to_chinese(9000)