Align vertical labels in subplots

mplalign.py

#!/usr/bin/env python

import matplotlib.pyplot as plt
import random
import matplotlib.gridspec as gridspec

random.seed(20)
data1 = [random.random() for i in range(10)]
data2 = [random.random()*1000 for i in range(10)]

gs = gridspec.GridSpec(2,1)
fig = plt.figure()

ax1 = fig.add_subplot(gs[0])
ax1.plot(data1)
ax1.set_ylabel(r'Label One', size =16)

ax2 = fig.add_subplot(gs[1])
ax2.plot(data2)
ax2.set_ylabel(r'Label Two', size =16)

### INTERESTING CODE BEGIN

# FIXME This can be done cleaner by patching _update_label_positions once
#       matplotlib 2.1.3 is released

def patch_axis(axis):
	def update(renderer):
		# Force recompute label positions
		ax1.yaxis._autolabelpos = ax2.yaxis._autolabelpos = True
		ax1.yaxis._get_tightbbox(renderer)
		ax2.yaxis._get_tightbbox(renderer)
		ax1.yaxis._autolabelpos = ax2.yaxis._autolabelpos = False
		# Update label positions
		(x1,y1) = ax1.yaxis.label.get_position()
		(x2,y2) = ax2.yaxis.label.get_position()
		ax1.yaxis.label.set_position((min(x1,x2), y1))
		ax2.yaxis.label.set_position((min(x1,x2), y2))

	old_draw = axis.draw
	def draw(renderer):
		update(renderer)
		return old_draw(renderer)
	axis.draw = draw

	old_get_tightbbox = axis._get_tightbbox = axis.get_tightbbox
	def get_tightbbox(renderer):
		update(renderer)
		return old_get_tightbbox(renderer)
	axis.get_tightbbox = get_tightbbox

patch_axis(ax1.yaxis)
patch_axis(ax2.yaxis)

### INTERESTING CODE END

plt.show()