To annotate bars with values on Python Pandas bar plots, we call the annotate metthod.
For instance, we write
for p in ax.patches:
ax.annotate(str(p.get_height()), (p.get_x() * 1.005, p.get_height() * 1.005))
to loop through the axes ax patches with ax.patches with a for loop.
Then we call ax.annotate to add the anootation for each patch by calling it with the position of the annotation.
