pycharm无法改变源

available packages里面没有manage那个修改源的选项，我是ubuntu里下载的

新版好像不能更换了

https://zhuanlan.zhihu.com/p/527821933?utm_id=0

https://jingyan.baidu.com/article/ae97a646b15eb5fafd461dab.html
https://blog.csdn.net/qq123456LX/article/details/115905156
https://blog.csdn.net/weixin_46348230/article/details/120676307

左下角。python packages.