如何在shell脚本中等待python脚本的执行？

Question

我想挂载另一个根分区，使用 python 脚本编辑 grub.cfg 文件，然后再次卸载该分区。如何等待 python 脚本完成并检查分区是否准备好卸载？目前我尝试使用等待，但这并不能解决问题。

if mountpoint $MPOINT; then
    echo "Already mounted. To prevent potential file loss aborting."
else
    echo "OK, will now mount the needed device."
    mkdir $MPOINT
    mount $DEVICE $MPOINT
    if [ $? -eq 0 ]; then
        # Edit config file
        python /usr/bin/grubcfgmgr.py "$MPOINT" &
        pid=$!
    else
        echo "Failed, could not mount. Aborting."
        rm -rf $MPOINT
        exit n
    fi

    # Umount
    wait $pid
    umount $MPOINT
    if [ $? -eq 0 ]; then
        echo "OK, umount was succesfull. Will delete empty mount point."
        rm -rf $MPOINT
    else
        echo "Failed, could not umount. Aborting."
    fi
fi