Python matplotlib decrease size of colorbar labels

I need your help! I have a plotting code which is the following:

fig = plt.figure()
ax1 = fig.add_subplot(111)

imax1 = ax1.imshow(data,interpolation = 'nearest', origin = 'lower',cmap=cm.jet)#plot
cbar = plt.colorbar(imax1, extend='neither', spacing='proportional',
                orientation='vertical', shrink=0.7, format="%.0f")
cbar.set_label(r"ET [mm/month]", size=10)

titlestr = "Evapotranspiration in mm/month"
plt.title(titlestr)
#plt.xlabel("Longitude")
#plt.ylabel("Latitude")
imax1.set_clim(0,60)
labels = [item.get_text() for item in ax1.get_xticklabels()]
for ii in range(np.shape(labels)[0]):
    labels[ii] = str(grid_lon[75*ii/np.shape(labels)[0]])

ax1.set_xticklabels(labels, rotation = 45, ha='right', size = 10)

labels = [item.get_text() for item in ax1.get_yticklabels()]
for ii in range(np.shape(labels)[0]):
    labels[ii] = str(grid_lat[75*ii/np.shape(labels)[0]])

ax1.set_yticklabels(labels, size = 10)

pngname = "./out/2d_"+variable+"_"+mm+".png"
print "save ", pngname
plt.savefig(pngname, dpi=None, facecolor='w', edgecolor='w',
    orientation='portrait', papertype=None, format=None,
    transparent=False, bbox_inches=None, pad_inches=0.1)


print "plot finished"

I would like to set the label size of the colorbar labels (e.g. 0,10,20,...60) to size of 10 or smaller. This will probably go into the line "imax1.set_clim(0,60). Any ideas? I'd be also interested to print information of the imax1 object to command line. How could I do that? E.g. available attributes and functions of imax1.

I deeply appreciate your help!

Aha! Found the answer here:

cbar.ax.tick_params(labelsize=10) 

P.S. Upvote that answer and give Paul some love!

If you are here because you're trying to increase font size, but some numbers disappear because of big size with the above answer, you can do

cbar = plt.colorbar()
for t in cbar.ax.get_yticklabels():
     t.set_fontsize(20)