Hi,

I have been learning python and I have recently written a little program that creates Hilbert curves which I submit to this list for critique and review:

# Hilbert Curve

# David Zuccaro
# 18/09/2014

import sys
import pygame
import math

class cursor:   
   
    def __init__(self, a): # a should be a list of 2 numbers ie a point.
        self.a = a

    def line(self, a):  
        # draw a line from he current position from the new position; update current position
        pygame.draw.lines(window, (255, 255, 255), True, [[self.a[0], self.a[1]], [self.a[0] + a[0], self.a[1] + a[1]]], 1)
        self.a[0] = self.a[0] + a[0]
        self.a[1] = self.a[1] + a[1]

    def hilbert(self, kind, order):
        row    = ((1,0,0,2), (0,1,1,3), (3,2,2,0), (2,3,3,1)) # hilbert curve definition table 0 = A 1 = B ...
        dir    = ((0,3,2),   (3,0,1),   (1,2,3),   (2,1,0)) # definition of A, B, C, D
        orient = ((0,-1), (-1,0), (0,1), (1,0))   # definition of up, left, down, right
        dist = 30 # length of segment
        if order > 0:
            for j in range(4):

                self.hilbert(row[kind][j], order - 1) # keep on hilberting until order = 0
               
                if j < 3:
                    self.line([x * dist for x in orient[dir[kind][j]]])

#this was the previous code but I thought it would be cleaner if
# more abstruse to do this all in one line ^

#                    if dir[kind][j] ==  0:            
#                        self.line(0, -dist) #up

#                    if dir[kind][j] ==  1:
#                        self.line(-dist, 0) #left

#                    if dir[kind][j] ==  2:
#                        self.line(0,dist)  #down

#                    if dir[kind][j] ==  3:
#                        self.line(dist, 0)   #right         


pygame.init()

#create the screen
window = pygame.display.set_mode((1900, 1000)) 

david = cursor([10,970])   # starting point increasing y moves down screen

david.hilbert(0, 5)  # create a fifth order hilbert curve

#draw it to the screen
pygame.display.flip()

#input handling (somewhat boilerplate code):
while True:
   for event in pygame.event.get():
      if event.type == pygame.QUIT:
          sys.exit(0)

#end

Output is here:
http://members.optuszoo.com.au/~david.zuccaro/hilbert2.png

https://en.wikipedia.org/wiki/Hilbert_curve