RTS mini-map

This is a base for a strategic mini-map often seen on RTS style games. Hopefully simple, definitely not finished, but still it works.

from direct.gui.OnscreenImage import OnscreenImage
from direct.gui.DirectGui import *
from direct.showbase.DirectObject import DirectObject
from pandac.PandaModules import *

class minimap(object):   #a strategic minimap to display on screen

	image = None	#the PNMImage
	onscreen = None		#the OnscreenImage to show mini-map on
	texture = None	# the texture image is saved to
	map = None		#the map as represented by a multi-dimensional array of many '1' and '2'.

	def __init__(self, map = None, onscreen = None):
		if map == None:		#if no map given, default image size
			self.image = PNMImage(256,256)
		else:	#if map given, image is size of map
			self.image = PNMImage(len(map[0]), len(map))
		self.image.write("minimap.png")		#saves the mini-map to hard drive (I just wanted to, not sure if necessary or not.)
		self.map = map
		self.texture = Texture()
		self.onscreen = onscreen

	def createmap(self, map):	#updates the map
		del self.image
		self.image = PNMImage(len(map[0]),len(map))		#if map size has changed, 
		for i in range(0, len(map)):
			for me in range(0, len(map[0])):
				if map[i][me] == 2:
					self.image.setXel( me , len(map)-1 - i , 0,1,0)
				if map[i][me] == 1:
					self.image.setXel( me , len(map)-1 - i , 0,0,1)				

	def __update__(self, map):		#a update function to be called every frame or every couple.
		self.createmap(map)	#update map
		self.texture.load(self.image)	#save map image to texture
		self.onscreen.setImage(self.texture)	#set onscreenimage to that texture