Matplotlib colorbar ticks on left/opposite side

You can switch the position of the ticks using c_ax.yaxis.set_ticks_position()

So for your example:

import matplotlib.pyplot as pltimport matplotlib as mplplt.viridis()fig=plt.figure()c_ax=plt.subplot(199)cb = mpl.colorbar.ColorbarBase(c_ax,orientation='vertical')c_ax.yaxis.set_ticks_position('left')plt.savefig('my_colorbar.png')

Note you can also move the colorbar label in a similar way:

c_ax.yaxis.set_label_position('left')

And finally, in case you have a horizontal colorbar, and want to move the ticks and labels to the top, you can use the equivalent function on the xaxis:

c_ax.xaxis.set_label_position('top')c_ax.xaxis.set_ticks_position('top')

I was having the same problem. This situation probably arises when you are setting explicitly the axes of the colorbar. In that case you can easily specify on what side of these axes you get the the ticks and the labels. For example, if you have created an image using imshow

fig = plt.figure()ax = plt.subplot(1, 1, 1)im = ax.imshow(data)

You can define the axis for the colorbar, in this example using inset_axes:

from mpl_toolkits.axes_grid1.inset_locator import inset_axescbaxes = inset_axes(ax, width="7%", height="20%", loc=4)

then add your colorbar

cb = fig.colorbar(im, cax=cbaxes, ticks=[vmin, vmax], orientation='vertical')

and then control the position of the ticks, etc...

cbaxes.yaxis.tick_left()

For some reason applying changes to the colorbar input axes (cax parameter) did not work for me.

However, grabbing the axes from the colorbar object and then applying the changes worked nicely:

cb.ax.xaxis.set_ticks_position("top")