python异常处理

try:
    except TypeError: #相当于if判断
    except 错误类型: #多个except elif
    except Exception as e: #如果所有的except都没捕获到，就走Exception
    else: #没有异常，走else语句
    finally: #总会被执行，不管有没有异常

In [4]: 1 + "2"                                                                 
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-4-db092cb74d2d> in <module>
----> 1 1 + "2"

TypeError: unsupported operand type(s) for +: 'int' and 'str'
# 这时程序报错会退出如果用 try处理，只会抛出异常,下面的程序会接着执行
In [5]: try: 
   ...:     1 + "2" 
   ...: except TypeError: 
   ...:     print('str to int error.') 
   ...: except Exception as e: 
   ...:     print(e) 
   ...: print('test') 
   ...:  
   ...:                                                                         
str to int error.
test

In [6]: try: 
   ...:     1 + abc 
   ...: except TypeError: 
   ...:     print('str to int error.') 
   ...: except Exception as e: 
   ...:     print(e) 
   ...:                                                                         
name 'abc' is not defined