Variable Property
Some interactive tkinter widgets have properties named variable or textvarible. Those properties can contain control variables, objects used to control the value behind the widget.
To define a variable, just put the variable's name in the property editor. Use the combo box to specify the type: StringVar, IntVar, DoubleVar or BooleanVar; StringVar is the default. See the tkinter documentation about how a widget manages each type.
You can link a "tkvariable" to a slider or entry widget and then programmatically access the changing value. These variables will be uninitialized until the user first operates the control.
In code, you can retrieve a reference of the tkinter variable using the builder method get_variable(name)
Add the following line to the generated Python code.
print('current value is ' , self.builder.get_variable('radiovar').get())
When you pull the slider back and forth with the mouse, it will print different numbers.
Interface file: controlvariables.ui
Full example code: controlvariables.py