Drawing the koch snowflake given n with python

import math
import numpy as np
import matplotlib.pyplot as plt
import sys

n = int(sys.argv[1])

def getp(p1,p2):
    z=complex(p2[0]-p1[0],p2[1]-p1[1])
    zr=complex(1/2,-3**(1/2)/2)
    z=z*zr
    p=[z.real+p1[0],z.imag+p1[1]]
    return p

ir=10
ip1=[0,0]
ip2=[ir,0]
ip3=[ir/2,ir/2*(3**(1/2))]
def gps(n):
    if n==0:
        return [ip1,ip2,ip3]
    else:
        points=gps(n-1)
        points.append(ip1)
        i=0 
        ls=[]
        #print(points)
        while(1):
            p1=points[i]
            p2=points[i+1]
            p11=[p1[0]+(p2[0]-p1[0])/3,p1[1]+(p2[1]-p1[1])/3]
            p12=[p1[0]+(p2[0]-p1[0])/3*2,p1[1]+(p2[1]-p1[1])/3*2]
            p=getp(p11,p12)
            ls.append(p1)
            ls.append(p11)
            ls.append(p)
            ls.append(p12)
            i=i+1
            if len(points)-1<i+1:
                break
        return ls

ps = gps(n)
print(ps)
ll = []
for p in ps: 
    ll.append(p[0])
ll.append(ps[0][0])
hl = []
for p in ps: 
    hl.append(p[1])
hl.append(ps[0][1])

left = np.array(ll)
height = np.array(hl)
plt.plot(left, height)
plt.show()

• n=5

Refs.

• plt.show