分组条形图:正确对齐

import matplotlib.pyplot as plt
import numpy as np

# 示例数据
categories = ['Category 1', 'Category 2']
sub_categories = ['Sub 1', 'Sub 2', 'Sub 3']
data = {
    'Category 1': [20, 34, 30],
    'Category 2': [15, 32, 34]
}

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

# 绘制分组条形图
fig, ax = plt.subplots()
for i, (category, values) in enumerate(data.items()):
    ax.bar(index + i * bar_width, values, bar_width, label=category)

# 设置图表标签和标题
ax.set_xlabel('Sub Categories')
ax.set_ylabel('Values')
ax.set_title('Grouped Bar Chart Example')
ax.set_xticks(index + bar_width / 2)
ax.set_xticklabels(sub_categories)
ax.legend()

plt.show()