GUIZero Flashing PushButton

from guizero import App, PushButton, Text

def buttonflash():
    if button.bg == "black":
        button.bg = "white"
    else:
        button.bg = "black"

app = App("Flashing Button")

text = Text(app, text="Here is a flashing button")
button = PushButton(app, text="Push Button")
button.bg = "black"
button.repeat(1000, buttonflash)

app.display()