Could not import backend for traitsui. Make sure you have a suitable UI toolkit like PyQt/PySide orC

这个报错是因为 traitsui 需要一个合适的 UI 工具包（如 PyQt、PySide 或 wxPython）来运行，但当前环境中没有安装这些工具包。traitsui 是一个用于创建用户界面的库，它依赖于这些工具包来渲染界面

可以安装：pyqt，或pyside

pip install PyQt5

如果pyqt已安装依旧报错：

那么:

pip install PySide

如果安装pyside时报错，显示版本问题，我安装pyside时报错：

The following packages are incompatible
└─ pyside is not installable because there are no viable options
   ├─ pyside 1.2.4 would require
   │  └─ qt 4.8* , which does not exist (perhaps a missing channel);
   └─ pyside 1.2.4 would require
      └─ qt 4.8.* , which does not exist (perhaps a missing channel).
 

那么重新安装pyside：

pip install PySide6

因为默认可能安装的该库版本较低