使用bokeh2.x中的annual_wedge在饼图/圆环图中添加标签

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

p = figure(plot_width=400, plot_height=400)

data = {'categories': ['A', 'B', 'C', 'D'],
        'values': [30, 20, 25, 15],
        'labels': ['Category A', 'Category B', 'Category C', 'Category D']}

source = ColumnDataSource(data)

p.annular_wedge(x=0, y=0, inner_radius=0.2, outer_radius=0.6,
                start_angle=[0.1, 0.3, 0.5, 0.7], end_angle=[1.1, 1.3, 1.5, 1.7],
                color=['#FF0000', '#00FF00', '#0000FF', '#FFFF00'],
                legend_label='categories', source=source)

labels = LabelSet(x=0, y=0, text='labels', level='glyph',
                  x_offset=0, y_offset=0, source=source,
                  render_mode='canvas', text_font_size='12pt')

p.add_layout(labels)

show(p)