Hexagonal Lattice

import math
%pylab inline

def createhex(xoff=1,yoff=1):
    A = (math.cos(math.radians(30)), math.sin(math.radians(30)))
    B = (math.cos(math.radians(90)), sin(math.radians(90)))
    C = (math.cos(math.radians(150)), sin(math.radians(150)))
    D = (math.cos(math.radians(210)), sin(math.radians(210)))
    E = (math.cos(math.radians(270)), sin(math.radians(270)))
    F = (math.cos(math.radians(330)), sin(math.radians(330)))
    G = (math.cos(math.radians(30)), math.sin(math.radians(30)))
    x,y = zip(A,B,C,D,E,F,G)
    x = [i + xoff for i in x]
    y = [i + yoff for i in y]
    return x,y
    
figsize(8,8)
xoffset = math.cos(math.radians(30))
yoffset = math.sin(math.radians(30))
for i in range(20):
    for j in range(20):
        xoff = j * xoffset * 2
        if i % 2 != 0:
            xoff += xoffset
        yoff = i * yoffset * 3
        x,y = createhex(xoff, yoff)
        plt.plot(x,y)