When using .ui files to build an interface graphically with QtDesigner, it is possible to load the interface directly from the .ui file rather than having to transform it onto python then import it. This is already integrated into PyQt4 and PyQt5, and relatively easy to implement in PySide as seen in python_qt_binding, the concurrent that doesn't support Qt5.

I know it's not the workflow used in spyder, but it would be a great utility for some projects (including mine).