Sharing axes between already created subplots

Question

I know I can create subplots with a shared axis with something like

import matplotlib.pyplot as plt
ax0 = plt.subplot(1,2,1)
ax1 = plt.subplot(1,2,2, sharex=ax0)

But, is there any way to share axes after ax1 was created? Something like

ax0 = plt.subplot(1,2,1)
ax1 = plt.subplot(1,2,2)

ax1.some_function(sharex=ax0)