如何在plotly中添加条形图上的百分比差异

import plotly.graph_objects as go
import numpy as np

# 示例数据
categories = ['A', 'B', 'C', 'D']
values1 = [30, 20, 40, 10]
values2 = [45, 25, 35, 15]

# 计算百分比差异
percent_diff = [(v2 - v1) / v1 * 100 if v1 != 0 else 0 for v1, v2 in zip(values1, values2)]

fig = go.Figure()

# 添加条形图
fig.add_trace(go.Bar(x=categories, y=values1, name='Initial'))
fig.add_trace(go.Bar(x=categories, y=values2, name='Final'))

# 添加百分比差异标注
for i, (cat, diff) in enumerate(zip(categories, percent_diff)):
    fig.add_annotation(
        x=cat,
        y=max(values1[i], values2[i]) + 1,  # 标注位置在两个条形图之上
        text=f'{diff:.1f}%',
        showarrow=False,
        font=dict(size=10, color='black')
    )

fig.update_layout(barmode='group', title='Percentage Difference in Bar Chart')
fig.show()