当X变量是分类变量时，如何在X轴上偏移错误条(matplotlib)

import matplotlib.pyplot as plt
import numpy as np

categories = ['A', 'B', 'C', 'D']
values = [10, 15, 12, 8]
errors = [1, 2, 1.5, 0.5]

fig, ax = plt.subplots()
ax.bar(categories, values, yerr=errors, align='center', alpha=0.5, ecolor='black', capsize=10)

ax.set_title('Bar Chart with Error Bars')
ax.set_xlabel('Categories')
ax.set_ylabel('Values')

ax.set_xticks(np.arange(len(categories)))
ax.set_xticklabels(categories)

plt.show()