Genetic Algorithm Demo Version1

#Genetic Algorithm Demo Version1
#By Nicolas Far nicofff (at) gmail.com
#August 2010

import random

def getRandomChar():
    RG=random.Random()
    return chr(RG.randint(ord('a'),ord('z')))

def getRandomInt(maxim):
    RG=random.Random()
    return RG.randint(0,maxim-1)

class Schromosome:
    def __init__(self,slen,string=''):
        if string!='':
            self.string=string
            return
        self.string=""
        for i in range(slen):
            self.string+=getRandomChar()

    def fitness(self,string):
        result=0
        for i in range(len(string)):
            result+=abs(ord(string[i])-ord(self.string[i]))
        return result

    def clone(self):
        result=""
        position=getRandomInt(len(self.string))
        for i in range(len(self.string)):
            if i != position:
                result+=self.string[i]
            else:
                result+=getRandomChar()
        return result

pop=50
population=[]
endString='holamundo'
for i in range(pop):
    population.append(Schromosome(len(endString)))
population.sort(key=lambda guy: guy.fitness(endString))

iteration=0
while True:
    guy=population[getRandomInt(pop)]
    prev=guy.fitness(endString)
    new=prev
    while prev<=new:
        newguy=Schromosome(0,guy.clone())
        new=newguy.fitness(endString)
    population[pop-1]=newguy
    population.sort(key=lambda guy: guy.fitness(endString))
    print ('iteration:',iteration,'best:',population[0].string)
    iteration+=1
    if newguy.string==endString:
        break