def _wait_for_device(dev):
    """Wait for device node to appear"""
    for i in xrange(0, FLAGS.block_device_creation_timeout):
        if os.path.exists(dev % '/dev/%s'):
            return
        time.sleep(1)

    raise StorageError(_('Timeout waiting for device %s to be created') % dev)
dataset/ETHPy150Open nii-cloud/dodai-compute/nova/virt/xenapi/vm_utils.py/_wait_for_device/swapped operands of `%`