JupyterNotebook安装插件管理包过程中报错( AttributeError module ‘tornado.web‘ has no attribute ‘asynchronous‘ )

1.报错信息

AttributeError: module 'tornado.web' has no attribute 'asynchronous'，

查看官方文档了解到 tornado.web.asynchronous在tornado5.1版本中已弃用，并在tornado6.0中已删除，用coroutines代替。

2.解决办法

网上给出的很多解决办法是 tornado6.0.4版本降级回到5.1.1

卸载命令：pip uninstall tornado

安装命令pip install tornado==5.1.1

不巧是还是报错,报错信息(依赖冲突):

ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
notebook 6.4.6 requires tornado>=6.1, but you have tornado 5.1.1 which is incompatible.

解决办法是: 升级一下nbconvert (至于为什么我也不是很清楚)

pip install --upgrade nbconvert

但是重要的是 升级后问题解决了。