Demo Colorbar of Inset Axes

import matplotlib.pyplot as plt

from mpl_toolkits.axes_grid1.inset_locator import inset_axes, zoomed_inset_axes
from mpl_toolkits.axes_grid1.colorbar import colorbar


def get_demo_image():
    from matplotlib.cbook import get_sample_data
    import numpy as np
    f = get_sample_data("axes_grid/bivariate_normal.npy", asfileobj=False)
    z = np.load(f)
    # z is a numpy array of 15x15
    return z, (-3, 4, -4, 3)


fig, ax = plt.subplots(figsize=[5, 4])

Z, extent = get_demo_image()

ax.set(aspect=1,
       xlim=(-15, 15),
       ylim=(-20, 5))


axins = zoomed_inset_axes(ax, 2, loc=2)  # zoom = 6
im = axins.imshow(Z, extent=extent, interpolation="nearest",
                  origin="lower")

plt.xticks(visible=False)
plt.yticks(visible=False)


# colorbar
cax = inset_axes(axins,
                 width="5%",  # width = 10% of parent_bbox width
                 height="100%",  # height : 50%
                 loc=3,
                 bbox_to_anchor=(1.05, 0., 1, 1),
                 bbox_transform=axins.transAxes,
                 borderpad=0,
                 )

colorbar(im, cax=cax)

plt.show()