To show a grid line on every tick, add
plt.grid(True)
For example:
import matplotlib.pyplot as plt
points = [
(0, 10),
(10, 20),
(20, 40),
(60, 100),
]
x = list(map(lambda x: x[0], points))
y = list(map(lambda x: x[1], points))
plt.scatter(x, y)
plt.grid(True)
plt.show()
In addition, you might want to customize the styling (e.g. solid line instead of dashed line), add:
plt.rc('grid', linestyle="-", color='black')
For example:
import matplotlib.pyplot as plt
points = [
(0, 10),
(10, 20),
(20, 40),
(60, 100),
]
x = list(map(lambda x: x[0], points))
y = list(map(lambda x: x[1], points))
plt.rc('grid', linestyle="-", color='black')
plt.scatter(x, y)
plt.grid(True)
plt.show()