fractalTree.py

#!/usr/bin/python2
# coding: utf-8

import cairo

class Saved():
    def __init__(self, cr):
        self.cr = cr
    def __enter__(self):
        self.cr.save()
        return self.cr
    def __exit__(self, type, value, traceback):
        self.cr.restore()

def Tree(angle):
    cr.move_to(0, 0)
    cr.translate(0, -260)
    cr.line_to(0, 0)
    cr.stroke()
    cr.scale(0.72, 0.72)
    if angle > 0.12:
        for a in [-angle, angle]:
            with Saved(cr):
                cr.rotate(a)
                Tree(angle * 0.85)

surf = cairo.ImageSurface(cairo.FORMAT_ARGB32, 1200, 900)
cr = cairo.Context(surf)
cr.translate(600, 899)
cr.set_line_width(5)
Tree(0.75)
surf.write_to_png('fractal-tree.png')