generators not working? python 2.2

[Mark McEahern]

I tried this simple example from:

  http://python.sourceforge.net/peps/pep-0255.html

and it doesn't seem to work?  I'm probably doing something obviously wrong.
Please help.

    $ python
    Python 2.2 (#1, Dec 31 2001, 15:21:18)
    [GCC 2.95.3-5 (cygwin special)] on cygwin
    Type "help", "copyright", "credits" or "license" for more information.
    >>> from __future__ import generators
    >>> def fib():
    ...     a, b = 0, 1
    ...     while 1:
    ...             yield b
    ...             a, b = b, a + b
    ...
    >>> for i in xrange(1, 10):
    ...     print fib().next()
    ...
    1
    1
    1
    1
    1
    1
    1
    1
    1

Thanks,

// mark