字符串分割：

方法一：列表综合，适用任意长度序列

[s[i:i+4] for i in range(0, len(seq), 4)]

方法二：re 模块，适用字符串，总长度要求是片段长度的整数倍

re.compile(r&'.{4}').findall(s)

方法三：struct 模块，适用字符串，总长度要求是片段长度的整数倍

struct.unpack(&'4s'*len(s)/4, s)

文件夹拷贝：

#!/usr/bin/env python
# encoding: utf-8

import os
import sys
import shutil

__doc__ = ''' copy all files from  directory to an destination ,
It recreate directory tree of src to dst and replace or create 
file in this directory.
If you have tree like this
src/A/dir/file
src/B/dir/sdir/file2
src/B/dir/file
and
then after script src dst 
dst/dir/file
dst/dir/sdir/file2 -> this is the B file2 wich is taken
http://code.activestate.com/recipes/577493-recurse-copy-file/
'''

def copytree(src, dst):
  if os.path.isdir(src):
    if not os.path.exists(dst):
      os.makedirs(dst)
    for name in os.listdir(src):
      copytree(os.path.join(src, name),
           os.path.join(dst, name))
  else:
    shutil.copyfile(src, dst)

def main(dsrc, ddst):
  for dirname in os.listdir(dsrc):
    tocopy = os.path.join(dsrc, dirname)
    for d in os.listdir(tocopy):
      src = os.path.join(tocopy,d)
      dst = os.path.join(ddst,d)
      if os.path.isdir(src):
        copytree(src, dst)

if __name__ == '__main__':
  src = sys.argv[1]
  dst = sys.argv[2]
  main(src, dst)

多行字符串：

>>> t = ('hello'
 ... ' '
 ... 'world')
>>> t
'hello world'