python的异常处理机制

names = ['a', 'b']data = {}try:    names[3]    data['name']except KeyError as e:    print('没有这个key',e)except IndexError as e:    print('列表操作错误',e)

names = ['a', 'b']data = {}try:    names[3]    data['name']except Exception as e:    print("出错了",e)

整体架子

names = ['a', 'b']data = {}try:    #names[3]    #data['name']    print(1)except (KeyError, IndexError) as e:    print("没有这个key", e)except IndexError as e:    print("列表操作错误", e)except Exception as e:    print("出错了", e)else:    print("一切正常")finally:    print("不管又错没错都执行")

自定义异常

# Author:danchengclass DanchengError(Exception):    def __init__(self, msg, msg1):        self.message = msg        self.message1 = msg1    # def __str__(self):    #     return 'sdfsf'try:    raise DanchengError('数据库连不上', 'ces')except DanchengError as e:    print(e)