PyPlot:隐藏轴但保留轴标签

PyPlot: hide axes but keep axis labels

我有以下代码:

import matplotlib.pyplot as plt

fig, axs = plt.subplots(1, 4)
for n, ax in enumerate(axs):
    ax.plot([1, 2], [1, 2])
    ax.set_xticks([])
    ax.set_yticks([])
    ax.set_xlabel(n)
plt.show()

...显示如下:

我想要的是隐藏黑框但保留标签。我试过添加 ax.set_axis_off() 但这也删除了标签:

我该怎么做?

把书脊的颜色改成None:

fig, axs = plt.subplots(1, 4)
for n, ax in enumerate(axs):
    ax.plot([1, 2], [1, 2])
    ax.set_xticks([])
    ax.set_yticks([])
    ax.set_xlabel(n)
    plt.setp(ax.spines.values(), color=None)
plt.show()