for this example to work you need to install the following packages in your conda environment:

```bash
pip install "perspective-python==3.8.0" pandas tornado
npm install -g @finos/perspective@3.8.0 @finos/perspective-viewer-d3fc@3.8.0 @finos/perspective-viewer-datagrid@3.8.0 @finos/perspective-viewer@3.8.0 @finos/perspective-workspace@3.8.0
```
