Is there any way to share Y axis among only part of subplots in matplotlib?

Yes, you can specify which suplots shares which axis with which axes (this is not a typo I mean this sentence). There’s a sharex and a sharey argument for add_subplot:

For example:

import numpy as np
import matplotlib.pyplot as plt

x = np.array([1,2,3,4,5])
y1 = np.arange(5)
y2 = y1 * 2
y3 = y1 * 5

fig = plt.figure()
ax1 = fig.add_subplot(131)                # independant y axis (for now)
ax1.plot(x, y1)
ax2 = fig.add_subplot(132, sharey=ax1)    # share y axis with first plot
ax2.plot(x, y2)
ax3 = fig.add_subplot(133)                # independant y axis
ax3.plot(x, y3)
plt.show()

this will create a plot like this (1^st and 2^nd share the y axis, but the 3^rd does not):

You can find another example of this in the matplotlib examples “Shared axis Demo”.