贴：python学习中引发错误程序遇到有关问题

求助贴：python学习中引发异常程序遇到问题
我是初学Python，属于菜鸟水平
我在运行以下程序时，如果输入ab，总提示我红色语句中x未被定义，去掉括号换成逗号后总说用类名定义x之间的逗号有问题，这是什么原因啊？我用的是Python3.2.3
class ShortInputException(Exception):
  '''A usere-defined exception class.'''
  def __init__(self,length,atleast):
  Exception.__init__(self)
  self.length=length
  self.atleast=atleast

try:
  s=input('Enter something->')
  if len(s)<3:
  raise ShortInputException(len(s),3)

except EOFError:
  print('\nWhy did you do an EOF on me?')
except ShortInputException(x):
  print('ShortInputException:The input was of length%d,\
  was expecting at least %d'%(x.length,x.atleast))
else:
  print('No exception was raised')


[解决办法]
except ShortInputException as x:
[解决办法]

Python code

except ShortInputException as x:
[解决办法]
在python3中，语法稍稍和python2.7不一样：
Assembly code
>>> try:...     print(1 / 0)... except Exception as exc:...     raise RuntimeError("Something bad happened") from exc...Traceback (most recent call last):  File "<stdin>", line 2, in <module>ZeroDivisionError: int division or modulo by zeroThe above exception was the direct cause of the following exception:Traceback (most recent call last):  File "<stdin>", line 4, in <module>RuntimeError: Something bad happened
[解决办法]
Python code
>>> try:...     print(1 / 0)... except Exception as exc:...     raise RuntimeError("Something bad happened") from exc...