Weasel program revisited with simple timing and testing functions

weasel_tester.py

import string, random, time

CHARS = string.uppercase + ' '
TEST = True

class Biosphere(object):
    '''Attempts to find `target` by producing generations of random strings that 
        mutate by `rate` percent. Generational population is determined by 
        `progeny`.
    '''

    def __init__(self, target='METHINKS IT IS LIKE A WEASEL', rate=0.05, progeny=100):
        self.target = target
        self.rate = rate        
        self.progeny = progeny
        
        self._genotype = lambda s : [random.choice(s) for x in xrange(len(self.target))]
        self.phenotypes = [''.join(self._genotype(CHARS)) for x in xrange(self.progeny)]
        self.population = [''.join(self._mutate(l)) for l in self.phenotypes]

        phenotype = ''
        i = 0
        while phenotype != self.target:

            points = [self._fitness(phenotype) for phenotype in self.population]
            winner = max(points)

            phenotype = self.population[points.index(winner)]
            self.population = [''.join(self._mutate(phenotype)) for x in xrange(self.progeny)] 

            print('%s: %s -- score: %s' % (i, phenotype, winner))
            i += 1
            self.i = i

    def _fitness(self, phenotype):
        return sum([x == y for x,y in zip(phenotype, self.target)])

    def _mutate(self, phenotype):
        return [(random.choice(CHARS) if random.random() < self.rate else c) for c in phenotype]

def prime(primer=5000):

    k = 0
    while k < primer:
        Biosphere('TEST')
        k += 1

def test(goal=10000):
    '''Test goal numbers of times, print average number of iterations.'''

    k = 0
    l = []
    while k < goal:
        b = Biosphere('TEST')
        l.append(b.i)
        k += 1
    
    print('Average: ' + str(float(sum(l)) / len(l)))
    print('Minimum: ' + str(min(l)))
    print('Maximum: ' + str(max(l)))

def timeit(func, *args):
    '''Simple timer wrapper for functions.'''

    start = time.time()
    func(*args)
    elapsed = time.time() - start
    
    return elapsed

if __name__ == '__main__':

    if TEST:
        #prime()
        secs = timeit(test)
        print('Time taken: %.2f secs' % secs)
    else:
        Biosphere()