python自定义异常实例详解

>raiseNameError('HiThere')
Traceback(most recent call last):
File"<pyshell#45>", line 1,in<module>
raiseNameError('HiThere')
NameError:HiThere

>classMyError(Exception):
def __init__(self, value):
      self.value = value
def __str__(self):
return repr(self.value)
>try:
raiseMyError(2*2)
exceptMyErroras e:
print('My exception occurred, value:', e.value)
My exception occurred, value:4
>raiseMyError('oops!')
Traceback(most recent call last):
File"<pyshell#64>", line 1,in<module>
raiseMyError('oops!')
MyError:'oops!'