dropdown#
from bokeh.io import show
from bokeh.models import CustomJS, Dropdown
menu = [("Item 1", "item_1"), ("Item 2", "item_2"), None, ("Item 3", "item_3")]
dropdown = Dropdown(label="Dropdown button", button_type="warning", menu=menu)
dropdown.js_on_event("menu_item_click", CustomJS(code="console.log('dropdown: ' + this.item, this.toString())"))
show(dropdown)