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 re

s = '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)