python matplotlib 坐标轴打断

想要绘制出如下类型坐标轴断开的图，matplotlib中并没有直接可用的API，但是官方给出了一个demo: broken axis.py
大概说下思路：画出两个共享X轴，完全相同的图，下图取消上边界，下图取消下边界，然后再使用plot画两组平行线就大功告成。

参照官网例子画的堆积图代码

    def respond_mode_bar(self):
        labels = ['Braking','Right','Left','R&B','L&B']
        # color_list = ['silver', 'red', 'blue', 'orange', 'deepskyblue']
        # color_list = ['blue', 'orange', 'green', 'red', 'olive']
        x = list(self.sub_list)
        y = np.zeros((len(self.sub_list), len(labels)), dtype=np.float)
        y0 = np.zeros(len(self.sub_list), dtype=np.float)
        # fig, (ax1, ax2) = plt.subplots(2, 1, sharex=True)
        gs = gridspec.GridSpec(2,1, height_ratios=[3,1], hspace=0.15)
        fig = plt.figure(figsize=(8, 4.5))
        ax1 = fig.add_subplot(gs[0,:])
        ax2 = fig.add_subplot(gs[1,:], sharex=ax1)
        ax1.set_ylim(70, 100)
        ax2.set_ylim(0, 10)

        ax1.spines['bottom'].set_visible(False)
        ax2.spines['top'].set_visible(False)
        ax1.xaxis.tick_top()
        ax1.tick_params(labeltop='off')  
        ax2.xaxis.tick_bottom()

        for idx, sub in enumerate (self.sub_list):
            sub = str(sub).zfill(4)
            y[idx,:] = np.array(self.data_dict[sub]['respond_mode'])
        for ii in range(len(labels)):
            if ii==0: ax1.bar(x, y[:,ii], align='center', \
                    label = labels[ii], width=0.6)
            if ii==0: ax2.bar(x, y[:,ii], align='center', \
                     label = labels[ii], width=0.6)
            else:
                y0 = y0 +y[:, ii-1]
                ax1.bar(x, y[:,ii], bottom=y0, align='center', \
                    label = labels[ii], width=0.6)
                ax2.bar(x, y[:,ii], bottom=y0, align='center', \
                    label = labels[ii], width=0.6)
        
        d = .01  # how big to make the diagonal lines in axes coordinates
        kwargs = dict(transform=ax1.transAxes, color='k', clip_on=False)
        ax1.plot((-d, +d), (-d, +d), **kwargs)        # top-left diagonal
        ax1.plot((1 - d, 1 + d), (-d, +d), **kwargs)  # top-right diagonal

        kwargs.update(transform=ax2.transAxes)  # switch to the bottom axes
        ax2.plot((-d, +d), (1 - d*3, 1 + d*3), **kwargs)  # bottom-left diagonal
        ax2.plot((1 - d, 1 + d), (1 - d*3, 1 + d*3), **kwargs)  # bottom-right diagonal

        plt.xlabel('Subject index')
        ax1.set_ylabel('Percentage (%)')
        plt.legend(loc=(0.65, 0.1), title='Evasive Maneuvers', \
                facecolor='w', framealpha=1)
        plt.savefig(self.fig_path+sub+'_respond_mode.png', dpi=300, transparent=True)
        plt.show()

官方参考
https://matplotlib.org/examples/pylab_examples/broken_axis.html