We could use the same handler for many different events (for example, a few similar events which happen on different widgets), and use this parameter to distinguish between them.Since in this case we are only using our handler for one kind of event, we will simply ignore the event parameter.All three of these widgets can display text (we could also make them display images).The label is a static element – it doesn’t keyword parameter when constructing each button to specify the function which should handle each button’s click events – both of these functions are object methods.Events are uniquely identified by a sequence name in string format – the format is described by a mini-language which is not specific to Python.Here are a few examples of common events: string variable object, and set a new value on the object whenever we want the text in the label to change.There are many ways in which we could organise our application class.In this example, our class doesn’t inherit from any is a method on the main window which we execute when we want to run our application.
We use the method on each widget to position it inside its parent – we will learn about different kinds of layout later.
GUIs often use a form of OO programming which we call whenever the user does something – for example, clicks on a button or types a keyboard shortcut.
Some events could also be triggered by occurrences which are not controlled by the user – for example, a background task might complete, or a network connection might be established or lost.
We also didn’t have to write our own function for closing the window, because there is already one defined as a method on the window object.
We did, however, write our own method for printing a message to the console.