change ticks font size matplotlib python
from matplotlib import pyplot as plt
from datetime import datetime, timedelta
xvalues = range(10)
yvalues = xvalues
fig,ax = plt.subplots()
plt.plot(xvalues, yvalues)
plt.xticks(fontsize=16)
# sets font size of xticks to 16 (respective of yticks)
plt.grid(True)
plt.show()