H90 合法IP python解法

def process(s):
    try:
        if len([i for i in s.split('.') if int(i)<=255 and int(i) >= 0])==4:
            return True
    except:
        return False
    return False

while True:
    try:
        if process(raw_input()):
            print "YES"
        else:
            print "NO"
    except Exception as e:
        break