字符串按每3个字符分割

# encoding: utf-8'''有字符串 'XXXxxxXXXxxxXXXxxxXXXxxxXXX'， 要求把该字符串按每3个字符分割, 返回一个列表。'''import res = 'XXXxxxXXXxxxXXXxxxXXXxxxXXX'def slice_string_1(org_str, step):    # 实现1    return [org_str[i: i+step] for i in xrange(0, len(org_str), step)]def slice_string_2(org_str, step):    # 实现2    return re.findall('.{%s}' % step, org_str)if __name__ == '__main__':   '''   result:   ['XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX']   ['XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX']   '''   step = 3   print slice_string_1(s, step)   print slice_string_2(s, step)