Python 学习笔记 13.异常(Exception)

转载自：http://www.xwy2.com/article.asp?id=124

Python 的异常处理机制和 C# 类似。

>>>>>> try:  
  raise Exception("a", "b")  
    except Exception,e:  
  print e  
    finally:  
  print "final"  
  
    
('a', 'b')('a', 'b')  
final  
>>>>>>   

同样可以处理多个异常筛选。

>>>>>> try:  
  raise EOFError("aa", "bb")  
    except RuntimeError, e:  
  print "[RuntimeErro]: ", e  
    except EOFError, e:  
  print "[EOFError]: ", e  
    except Exception, e:  
  print "[Error]: ", e  
    finally:  
  print "final"  
  
    
[EOFError]:  ('aa', 'bb')  
final  
>>>>>>   

除了异常参数，我们还可以用sys的一些方法来获取异常信息。

>>>>>> import sys  
>>>>>> try:  
  raise RuntimeError("the runtime error raised")  
    except:  
  print sys.exc_info()  
  
    
(<type 'exceptions.RuntimeError'>, RuntimeError('the runtime error raised',), <traceback object at 0x00DC5CB0>)  
>>>>>>   

缺省情况下，异常类都继承自 Exception。

>>>>>> class MyException(Exception):  
  pass  
  
>>>>>> try:  
  raise MyException("My Exception raised!")  
    except:  
  print sys.exc_info()  
  
    
(<class '__main__.MyException'>, MyException('My Exception raised!',), <traceback object at 0x00DC58F0>)  
>>>>>>