解决vscode中yapf无法格式化python代码的问题

参考了许多解答，最后在stackoverflow上找到了正解
How to use yapf (or black) in VSCode
关键是yapf参数设置，配置见下方

{
    "editor.formatOnSave": true,
    "python.formatting.provider": "yapf",
    "python.formatting.yapfArgs": [
        "--style={based_on_style: pep8, indent_width: 4}"
    ],
}