ম্যাটপ্লটলিব contour

import matplotlib.pyplot as plt

x = [1, 2, 3, 4]
y = [1, 2, 3, 4]

z = [
    [1, 2, 3, 4],
    [2, 3, 4, 5],
    [3, 4, 5, 6],
    [4, 5, 6, 7]
]

plt.contour(x, y, z)

plt.show()