将百分比添加到Bokeh Donut图表

from bokeh.plotting import figure, show
from bokeh.models import ColumnDataSource, LabelSet
from bokeh.io import output_notebook

data = {'category': ['A', 'B', 'C', 'D'],
        'value': [30, 20, 25, 15]}
source = ColumnDataSource(data=data)

p = figure(plot_height=400, plot_width=400, title="Donut Chart",
           tools="hover", tooltips="@category: @value%", x_range=(-1, 1))

p.wedge(x=0, y=0, radius=0.4, start_angle='start_angle', end_angle='end_angle',
        line_color="white", fill_color='color', legend_field='category', source=source)

p.axis.axis_label=None
p.axis.visible=False
p.grid.grid_line_color = None

start_angle = [0] + [2 * pi * i / sum(data['value']) for i in range(len(data['value']))]
end_angle = [2 * pi * i / sum(data['value']) for i in range(1, len(data['value'])+1)]
data['start_angle'] = start_angle
data['end_angle'] = end_angle

labels = LabelSet(x=0, y=0, text='value%', level='glyph',
                  text_font_size='12pt', text_color='white',
                  source=source, render_mode='canvas')

p.add_layout(labels)

output_notebook()
show(p)