button_icon

from bokeh.io import show
from bokeh.models import BuiltinIcon, Button, SetValue

icon = BuiltinIcon("settings", size="1.2em", color="white")
button = Button(label="Foo", icon=icon, button_type="primary")
button.js_on_event("button_click", SetValue(button, "label", "Bar"))

show(button)