plt.xticks(fontsize=14, rotation=90)
ax.tick_params(axis='both', which='major', labelsize=10)
import matplotlib.pyplot as plt
# We prepare the plot
fig, ax = plt.subplots()
# We change the fontsize of minor ticks label
ax.tick_params(axis='both', which='major', labelsize=10)
ax.tick_params(axis='both', which='minor', labelsize=8)