L-systems 0.0.1

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

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

axiomF='F--F--F'
rulesF = {}
rulesF['F'] = 'F+F--F+F'


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

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

iterate(axiomB,rulesB,6)
iterate(axiomA,rulesA,6)
iterate(axiomF,rulesF,6)

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