python面向对象--异常处理
1.常见异常类型
IOError 文件读写异常
ValueError值异常，一般是数据类型不对应
IndexError下标索引越界
2.try...except...
try:
f=open('test.txt')
except IOError as e:
print(e)
>>:
[Errno 2] No such file or directory: 'test.txt' 3.错误基类Exception
try:
print(a)
except Exception as e:
print(e)
>>:
name 'a' is not defined 4.else没发生异常就执行
5.finally无论如何都执行
6.raise主动触发异常
raise ImportError
>>:
*Traceback (most recent call last):
File "D:/PycharmProjects/untitled2/test.py", line 9, in <module>
raise ImportError
ImportError*