如何使用matplotlib创建堆叠条形图？

import matplotlib.pyplot as plt
import numpy as np

categories = ['A', 'B', 'C', 'D']  # 类别
data1 = [10, 15, 20, 12]  # 数据集1
data2 = [8, 12, 10, 15]  # 数据集2
data3 = [5, 10, 15, 8]  # 数据集3

fig, ax = plt.subplots()

# 设置条形图的位置和宽度
bar_width = 0.35
bar_positions = np.arange(len(categories))

# 绘制堆叠条形图
ax.bar(bar_positions, data1, bar_width, label='Data 1')
ax.bar(bar_positions, data2, bar_width, bottom=data1, label='Data 2')
ax.bar(bar_positions, data3, bar_width, bottom=np.array(data1) + np.array(data2), label='Data 3')

# 设置图表标题和坐标轴标签
ax.set_title('Stacked Bar Chart')
ax.set_xlabel('Categories')
ax.set_ylabel('Values')

# 设置图例
ax.legend()

# 设置x轴刻度标签
ax.set_xticks(bar_positions)
ax.set_xticklabels(categories)

# 显示图表
plt.show()