Buggy python submission (verdict: Runtime Error):
import math
sin60 = math.sin(60*math.pi/180)
def koch(n,p1,p2):
    if n==0:
        return
    s = [ ( 2*p1[0] + 1*p2[0] ) / 3 , ( 2*p1[1] + 1*p2[1]) / 3 ]
    t = [ ( 1*p1[0] + 2*p2[0] ) / 3 , ( 1*p1[1] + 2*p2[1]) / 3 ]
    u = [ ( t[0] - s[0] ) *0.5 - ( t[1] - s[1] )*sin60 + s[0],
        ( t[0] - s[0] )*sin60 + ( t[1] - s[1] )*0.5 + s[1] ]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n  = raw_input()
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]

Fixed submission:
import math
sin60 = math.sin(60*math.pi/180)
def koch(n,p1,p2):
    if n==0:
        return
    s = [(2*p1[0]+1*p2[0])/3., (2*p1[1]+1*p2[1])/3.]
    t = [(1*p1[0]+2*p2[0])/3., (1*p1[1]+2*p2[1])/3.]
    u = [(t[0]-s[0])*0.5 - (t[1]-s[1])*sin60+ s[0],
        (t[0]-s[0])*sin60 + (t[1]-s[1])*0.5 + s[1]]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n = int(raw_input())
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]

Buggy python submission (verdict: Runtime Error):
import math
sin60 = math.sin(60*math.pi/180)
def koch(n,p1,p2):
    if n==0:
        return
    s = [ ( 2*p1[0] + 1*p2[0] ) / 3. , ( 2*p1[1] + 1*p2[1]) / 3. ]
    t = [ ( 1*p1[0] + 2*p2[0] ) / 3. , ( 1*p1[1] + 2*p2[1]) / 3. ]
    u = [ ( t[0] - s[0] ) *0.5 - ( t[1] - s[1] )*sin60 + s[0],
        ( t[0] - s[0] )*sin60 + ( t[1] - s[1] )*0.5 + s[1] ]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n  = raw_input()
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]

Fixed submission:
import math
sin60 = math.sin(60*math.pi/180)
def koch(n,p1,p2):
    if n==0:
        return
    s = [(2*p1[0]+1*p2[0])/3., (2*p1[1]+1*p2[1])/3.]
    t = [(1*p1[0]+2*p2[0])/3., (1*p1[1]+2*p2[1])/3.]
    u = [(t[0]-s[0])*0.5 - (t[1]-s[1])*sin60+ s[0],
        (t[0]-s[0])*sin60 + (t[1]-s[1])*0.5 + s[1]]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n = int(raw_input())
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]

Buggy python submission (verdict: Runtime Error):
import math

def koch(n,p1,p2):
    if n==0:
        return
    s = [(2*p1[0]+1*p2[0])/3, (2*p1[1]+1*p2[1])/3]
    t = [(1*p1[0]+2*p2[0])/3, (1*p1[1]+2*p2[1])/3]
    u = [(t[0]-s[0])*0.5 - (t[1]-s[1])*sin60+ s[0],
        (t[0]-s[0])*sin60 + (t[1]-s[1])*0.5 + s[1]]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n = int(raw_input())
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]

Fixed submission:
import math
sin60 = math.sin(60*math.pi/180)
def koch(n,p1,p2):
    if n==0:
        return
    s = [(2*p1[0]+1*p2[0])/3., (2*p1[1]+1*p2[1])/3.]
    t = [(1*p1[0]+2*p2[0])/3., (1*p1[1]+2*p2[1])/3.]
    u = [(t[0]-s[0])*0.5 - (t[1]-s[1])*sin60+ s[0],
        (t[0]-s[0])*sin60 + (t[1]-s[1])*0.5 + s[1]]
    koch(n-1,p1,s)
    print s[0],s[1]
    koch(n-1,s,u)
    print u[0],u[1]
    koch(n-1,u,t)
    print t[0],t[1]
    koch(n-1,t,p2)
        
n = int(raw_input())
p1 = (0,0)
p2 = (100,0)
print p1[0],p1[1]
koch(n,p1,p2)
print p2[0],p1[1]