使用pandas绘制按另一列分组的单个列的三重条形图

import pandas as pd
import matplotlib.pyplot as plt

data = pd.DataFrame({'group': ['A', 'A', 'B', 'B', 'C', 'C'],
                     'category': ['X', 'Y', 'X', 'Y', 'X', 'Y'],
                     'value': [10, 15, 8, 12, 6, 9]})

grouped_data = data.groupby('group')['value'].sum()

fig, ax = plt.subplots(figsize=(8, 6))

bar_width = 0.2
index = range(len(grouped_data))
ax.bar(index, grouped_data['A'], bar_width, label='Group A')
ax.bar([i + bar_width for i in index], grouped_data['B'], bar_width, label='Group B')
ax.bar([i + 2 * bar_width for i in index], grouped_data['C'], bar_width, label='Group C')

ax.set_xlabel('Category')
ax.set_ylabel('Value')
ax.set_title('Triple Bar Chart by Group')
ax.set_xticks([i + bar_width for i in index])
ax.set_xticklabels(grouped_data.index)
ax.legend()

plt.show()