Put a title on the right y axis of a matplotlib axes using the set_title API.

right_side_title.py

import matplotlib as mpl
import matplotlib.pyplot as plt

f, ax = plt.subplots(figsize=(5, 5))
ax.set_title("Col title", y=1)
title = ax.set_title(
    "Row title", loc="right", y=.5,
    rotation=270, ha="left", va="center",
)
offset_trans = mpl.transforms.ScaledTranslation(
    mpl.rcParams["axes.titlepad"] / 72, 0, ax.figure.dpi_scale_trans
)
title.set_transform(ax.transAxes + offset_trans)