Changing the tick frequency on the x or y axis

I am trying to fix how python plots my data. Say:

x = [0, 5, 9, 10, 15]
y = [0, 1, 2, 3, 4]

matplotlib.pyplot.plot(x, y)
matplotlib.pyplot.show()

The x axis' ticks are plotted in intervals of 5. Is there a way to make it show intervals of 1?