pycharm项目根目录作为Python导包路径的说明

之前知道pycharm会将项目根目录作为Python导包路径，今天想看看官方文档说明，如下：

Source roots  contain the actual source files and resources. PyCharm uses the source roots as the starting point for resolving imports

https://www.jetbrains.com/help/pycharm/configuring-project-structure.html