import numpy as np
import matplotlib.pyplot as plt

x = np.array([0, 1, 1, 0, 0])
y = np.array([0, 0, 1, 1, 0])

fig, ax = plt.subplots()
ax.plot(x, y)
ax.axis("equal")
ax.axis([-1, 2, -1, 2])

plt.show()