def __init__(self, filename, start, stop):
        self.filename = filename
        self.fileobj = open(self.filename, 'rb')
        if start:
            self.fileobj.seek(start)
        if stop is not None:
            self.length = start - stop
        else:
            self.length = None
dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/scripts/eggsrv.py/FileIterator.__init__/swapped operands of `-`