men_means = (85.5,91.0,72.0,59.0,66.0,55.0) women_means = (94.0,82.0,89.5,62.0,49.0,53.0)绘制堆积柱形图。堆积柱形图的x轴为学科，y轴为平均成绩

以下是使用matplotlib库绘制堆积柱形图的代码：

import matplotlib.pyplot as plt
import numpy as np

# 数据
men_means = (85.5, 91.0, 72.0, 59.0, 66.0, 55.0)
women_means = (94.0, 82.0, 89.5, 62.0, 49.0, 53.0)
subjects = ('Math', 'English', 'History', 'Science', 'Art', 'Music')

# 绘图
fig, ax = plt.subplots()
ax.bar(subjects, men_means, label='Men')
ax.bar(subjects, women_means, bottom=men_means, label='Women')

# 图例
ax.legend()

# 标题和轴标签
ax.set_title('Average scores by subject and gender')
ax.set_xlabel('Subjects')
ax.set_ylabel('Average score')

# 显示图形
plt.show()

绘制出来的堆积柱形图如下所示：