# Test case taken from test_itertools # See http://mail.python.org/pipermail/python-dev/2005-November/058339.html from itertools import tee def leak(): def fib(): def yield_identity_forever(g): while 1: yield g def _fib(): for i in yield_identity_forever(head): yield i head, tail, result = tee(_fib(), 3) return result x = fib() x.next()