name = [0, 1, 2]

try:

    name[3]

except IndexError as exc:  # 抓单个错误，打印错误信息e

    print(exc)

except (IndexError, KeyError) as exc:  # 同时抓多个错误，不推荐！！

    print(exc)

except Exception as exc:  # 抓所有错误

    print(exc)

else:

    print('一切正常')   # 一切正常时执行

finally:

    print('不管有错没错，都执行')   # 总是执行

try:

    f = open('missing')

except OSError:   # 先执行OSError

    print('It failed')

except FileNotFoundError:

    print('File not found')

>>>FileNotFoundError.__mro__  # 或FileNotFoundError.mro()

[<class 'FileNotFoundError'>, <class 'OSError'>, <class 'Exception'>, <class 'BaseException'>, <class 'object'>]

try:

    int('N/A')

except ValueError as e:

    print("didn't work：", e)

    raise   # 用raise重新抛出上一个异常

#didn't work： invalid literal for int() with base 10: 'N/A'

#ValueError: invalid literal for int() with base 10: 'N/A'

class MyException(Exception):

    def __init__(self, msg):

        self.message = msg

    def __str__(self):

        return self.message

raise MyException('not a valid password')  # 调用自定义异常

class AddressValueError(ValueError):

    """A Value Error related to the netmask."""

raise AddressValueError('not a valid address')   # 调用继承了ValueError异常的自定义异常