http://en.wikipedia.org/wiki/Look-and-say_sequence

look_and_say.py

def look_and_say(member):
    while True:
        num = [] 
        count = []
        pre = None
        for ele in member:
            if len(num) > 0 and pre == ele:
                count[len(count)-1] += 1
            else:
                num += [ele]
                count += [1]
                pre = ele
        member = ''.join([''.join([ str(i) for i in pair]) for pair in zip(count, num)])
        yield member

这个作为面试题到也不错~
可以考考思维，代码的组织，以及python的list，yield的运用：

for i in look_and_say('11'):
print i