CODE EXAMPLE FOR PYTHON

heatmap colorbar label

import seaborn as sns
import pandas as pd
data = pd.DataFrame({'x':(1,2,3,4),'y':(1,2,3,4),'z':(14,15,23,2)})

sns.heatmap(data.pivot_table(index='y', columns='x', values='z'), 
                             cbar_kws={'label': 'colorbar title'})