Delaunay Triangulation Grid Python

#!/usr/bin/env python
import matplotlib.pyplot as plt
import matplotlib.tri as tri
import numpy as np
import math
from scipy.interpolate import griddata
data = np.genfromtxt('input.txt')
x = data[:,0]
y = data[:,1]
triang = tri.Triangulation(x, y)

# Plot the triangulation.
plt.figure()
plt.gca().set_aspect('equal')
plt.triplot(triang, 'bo-')
plt.title('Triplot of Delaunay triangulation')
plt.show()