L-Systems 0.0.4

from turtle import *


axiomA='A'
rulesA = {}
rulesA['A'] = 'AB'
rulesA['B'] = 'A'

axiomB='B'
rulesB = {}
rulesB['B'] = 'BA'
rulesB['A'] = 'B'

axiomF='F'
rulesF = {}
rulesF['F'] = 'F+F-F-F+F'
turtleRulesF = {}
turtleRulesF['F'] = 'forward(10)'
turtleRulesF['+'] = 'left(90)'
turtleRulesF['-'] = 'right(90)'

axiomS='A'
rulesS = {}
rulesS['A'] = 'B-A-B'
rulesS['B'] = 'A+B+A'
turtleRulesS = {}
turtleRulesS['A'] = 'forward(3)'
turtleRulesS['B'] = 'forward(3)'
turtleRulesS['+'] = 'left(60)'
turtleRulesS['-'] = 'right(60)'

axiomD='FX'
rulesD={}
rulesD['X']='X+YF'
rulesD['Y']='FX-Y'
turtleRulesD={}
turtleRulesD['F'] = 'forward(5)'
turtleRulesD['-'] = 'left(90)'
turtleRulesD['+'] = 'right(90)'
turtleRulesD['X'] = 'nul'
turtleRulesD['Y'] = 'nul'


def compose(axiom, rules):
        output = ""
        for i in axiom:
            output = output + rules.get(i,i)
        return output

def iterate(axiom,rules, times):
    output = ''
    if times == 0:
        output = axiom
    else:
        return iterate(compose(axiom, rules), rules, times -1)
    return output

#print iterate(axiomA,rulesB,6)
#print iterate(axiomB,rulesA,6)
#directions = iterate(axiomF,rulesF,3)
#print directions

def evaluate(axiom,rules,turtleRules,times):
    for words in iterate(axiom,rules,times):
        if turtleRules[words] != 'nul':
            eval(turtleRules[words])
screensize(800,800)
speed(0)
pu()
#setx(-400)
#sety(-400)
pd()
color('red','yellow')
#begin_fill()
#evaluate(axiomS,rulesS,turtleRulesS,6)
evaluate(axiomD,rulesD,turtleRulesD,10)
#end_fill()
done()

#special thanks to http://www.4dsolutions.net/ocn/lsystems.html