Commands
Widgets in guizero can be given a command
when created, which can be used to call a function when the widget is used.
By using commands you can make your GUI change and take actions when the user uses it e.g. clicking a button, selecting an option, typing a message.
Example
Create an application which puts hello world
on the GUI when a button is pressed:
from guizero import App, Text, PushButton
def say_hello():
text.value = "hello world"
app = App()
text = Text(app)
button = PushButton(app, command=say_hello)
app.display()