[PyQt] Newbe question about Print() to PyQt

[Larz60+]

In Gui Programming, you 'print' to widgets in different ways, depending on the type of widget.
Almost always passed as an argument.
I don't see anywhere in your code the definition of 'screen'

What kind of widget is being used?

There are many widgets that have text attributes, see: http://doc.qt.io/qt-5/examples-widgets.html

usually to display 'text' the attribute is something like text='value', but not always,