title: Python matplotlib decrease size of colorbar labels
body: <p>I need your help! I have a plotting code which is the following:</p>
  
  <pre><code>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"
  </code></pre>
  
  <p>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.</p>
  
  <p>I deeply appreciate your help!</p>