alt Hacker Newsthis should do the trick...
while creatures:
c = get_random_creature()
if c.is_dead():
creatures.pop(c)
else:
creatures.add(c.mutate())this should do the trick...
while creatures:
c = get_random_creature()
if c.is_dead():
creatures.pop(c)
else:
creatures.add(c.mutate())
You also need selection, not just mutation (I know you are being silly, so am I)