raising.py

《python编程金典》书中

#!/usr/bin/python
# -*- coding: cp936 -*-
#fielname:raising.py
class ShortInputException(Exception):
     '''自己定义的输入字符串太短的异常类

抛出ShortInputException异常'''
     def __init__(self,length,atleast):
          Exception.__init__(self)
          self.length=length
          self.atleast=atleast

try:
     s=raw_input("请你输入一个字符串")
     if len(s)<3:
          raise ShortInputException(len(s),3)
except ShortInputException,x:
     print "你输入的字符串太短，你的输入是%d,期望得到%d"%(x.length,x.atleast)
else:
     print"没有异常发生"