如何将第二行标签添加到matplotllib条形图的x轴？

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]
y = [10, 15, 7, 12, 9]
plt.bar(x, y)

second_labels = ['A', 'B', 'C', 'D', 'E']
second_label_positions = [1.5, 2.5, 3.5, 4.5, 5.5]

plt.xticks(second_label_positions, second_labels)

plt.title('Bar Chart with Second Line Labels')
plt.xlabel('X Label')
plt.ylabel('Y Label')

plt.show()