Plot 2

import matplotlib.pyplot as plt
import numpy as np
from scipy import interpolate

def Lag(x, i, t):
    produit = 1
    for j in range(0, len(x)):
        if i != j:
            produit *= (t - x[j])/(x[i]-x[j])
    return produit

def Interp(x, y, t):
    somme = 0
    for i in range(0, len(x)):
        somme += y[i] * Lag(x, i, t)

    return somme

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

plt.ylim((-3,3))
plt.xlim((-3,3))
for i in range(0, 4):
    xR = np.linspace(-3, 3)
    yR = []
    for j in xR:
        yR.append(Interp(x, y, j))
    plt.plot(x[i], y[i], "o")
    plt.plot(xR, yR)
    plt.show()