[python] Python xticks in subplots

If I plot a single imshow plot I can use

fig, ax = plt.subplots()
ax.imshow(data)
plt.xticks( [4, 14, 24],  [5, 15, 25] )

to replace my xtick labels.

Now, I am plotting 12 imshow plots using

f, axarr = plt.subplots(4, 3)
axarr[i, j].imshow(data)

How can I change my xticks just for one of these subplots? I can only access the axes of the subplots with axarr[i, j]. How can I access plt just for one particular subplot?

See the (quite) recent answer on the matplotlib repository, in which the following solution is suggested:

• If you want to set the xticklabels:

  ax.set_xticks([1,4,5]) 
  ax.set_xticklabels([1,4,5], fontsize=12)
  

• If you want to only increase the fontsize of the xticklabels, using the default values and locations (which is something I personally often need and find very handy):

  ax.tick_params(axis="x", labelsize=12) 
  

• To do it all at once:

  plt.setp(ax.get_xticklabels(), fontsize=12, fontweight="bold", 
           horizontalalignment="left")`