Python 3, module ‘itertools’ has no attribute ‘ifilter’

itertools.ifilter() was removed in Python 3 because the built-in filter() function provides the same functionality now.

If you need to write code that can run in both Python 2 and Python 3, use imports from the future_builtins module (only in Python 2, so use a try...except ImportError: guard):

try:
    # Python 2
    from future_builtins import filter
except ImportError:
    # Python 3
    pass

return filter(lambda i: i.state == "IS", self.storage)