hover = HoverTool(
tooltips=[
("Vehicle", "@name, 19@yr"),
("MPG", "@mpg"),
("Engine", "@displ cu in @cyl cylinder @hp HP"),
]
)
cmap = dict(zip([1,2,3], 'red green blue'.split()))
omap = dict(zip([1,2,3], 'American European Asian'.split()))
origin = [omap[o] for o in autompg.origin]
autompg['colors'] = [cmap[o] for o in autompg.origin]
autompg['origin_tag'] = autompg.origin.map({1: 'American', 2: 'European', 3:'Asian'})
p = figure(tools=[hover], width=800, height=400)
p.circle('mpg', 'weight', color='colors', size=10, alpha=0.3, source=ColumnDataSource(autompg), legend='origin_tag')
show(p)