problem with change to exceptions

[Neal Becker]

import exceptions

class nothing (exceptions.Exception):
    def __init__ (self, args=None):
        self.args = args

if __name__ == "__main__":
    raise nothing

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/tmp/python-3143hDH", line 5, in __init__
    self.args = args
TypeError: 'NoneType' object is not iterable

I'll have to say, I don't understand this error.