[formerly_proven]

PyQt is a really good binding. Compared to e.g. wxPython (Phoenix), which is built using PyQt's tooling, the latter is full of jank, like whether something is a property seems to be random (SetIcon(icon) -> property, SetIcons(iconbundle) -> not a property, just one funny example). Some things ARE properties, but they're not writeable, even if there actually is a SetXXX method. Some things convert types automatically, some don't. In a bunch of cases there is weirdness, like what you return from a OnGetAttr needs to be protected from Python GC, otherwise it is silently (!?) ignored. Add the jank of wxWidgets itself, and PyQt/PySide look even better.