x轴坐标斜着显示set_xticklabels(tt.index,rotation=45)

# 修改x轴显示
fig = plt.figure(figsize=(10,5))
ax = fig.add_subplot(111)
xticks = range(0,len(tt.index), 1)
xlabels = [el for el in tt.index]
ax.set_xticks(xticks)