Add unit to yaxis labels in MatPlotLib

I am trying to add mi or km (miles, kilometers) after the value on the yaxis of a matplotlib bar chart.

Right now I am just supplying matplotlib the values and it is making the yaxis labels automatically. I can't figure out how to append mi to the end of a value.

24 > 24 mi

There is an option for ax.set_7ticklabels(), but then I would need to set them statically.

Are you wanting something like this?

import matplotlib.pyplot as plt
from matplotlib.ticker import FormatStrFormatter

x = range(10)
plt.plot(x)

plt.gca().xaxis.set_major_formatter(FormatStrFormatter('%d km'))

plt.show()