Python实现目录文件的全量和增量备份

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目标：

1.传入3个参数:源文件路径，目标文件路径，md5文件

2.每周一实现全量备份，其余时间增量备份

1.通过传入的路径，获取该路径下面的所有目录和文件(递归)

方法一：使用os.listdir

代码如下：

#!/usr/bin/env python
#coding:utf8import os,sysdef lsdir(folder):
contents = os.listdir(folder)
print "%s\n%s\n" % (folder, contents)
for path in contents:
full_path = os.path.join(folder, path)
if os.path.isdir(full_path):
lsdir(full_path)if __name__ == "__main__":
lsdir(sys.argv[1])

•运行代码，效果如下：

[root@localhost python]# python listdir.py /a
/a
['b', 'a.txt']/a/b
['c', 'b.txt']/a/b/c
['c.txt']

方法二：使用os.walk

代码如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-import os,sysdef lsdir(folder):
contents = os.walk(folder)
for path, folder, file in contents:
print "%s\n%s\n" %(path, folder + file)if __name__ == "__main__":
lsdir(sys.argv[1])

•运行代码，测试效果

[root@localhost python]# python listdir1.py /a
/a
['b', 'a.txt']/a/b
['c', 'b.txt']/a/b/c
['c.txt']

2.如何计算文件的md5值(每次读取4K，直到读取完文件所有内容，返回一个16进制的md5值)

代码如下：

[root@localhost python]# cat md5.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-import hashlib
import sysdef md5(fname):
m = hashlib.md5()
with open(fname) as fobj:
while True:
data = fobj.read(4096)
if not data:
break
m.update(data)
return m.hexdigest()if __name__ == "__main__":
print md5(sys.argv[1])

•运行代码，测试效果

[root@localhost python]# python md5.py a.txt
c33da92372e700f98b006dfa5325cf0d
[root@localhost python]# md5sum a.txt
c33da92372e700f98b006dfa5325cf0d a.txt

*提示：使用linux自带的md5sum和自己编写的Python计算的md5值相通

3.编写全量和增量备份脚本

代码如下：

#!/usr/bin/env python
#coding:utf8import time
import os
import tarfile
import cPickle as p
import hashlibdef md5check(fname):
m = hashlib.md5()
with open(fname) as fobj:
while True:
data = fobj.read(4096)
if not data:
break
m.update(data)
return m.hexdigest()def full_backup(src_dir, dst_dir, md5file):
par_dir, base_dir = os.path.split(src_dir.rstrip('/'))
back_name = '%s_full_%s.tar.gz' % (base_dir, time.strftime('%Y%m%d'))
full_name = os.path.join(dst_dir, back_name)
md5dict = {} tar = tarfile.open(full_name, 'w:gz')
tar.add(src_dir)
tar.close()
for path, folders, files in os.walk(src_dir):
for fname in files:
full_path = os.path.join(path, fname)
md5dict[full_path] = md5check(full_path) with open(md5file, 'w') as fobj:
p.dump(md5dict, fobj)def incr_backup(src_dir, dst_dir, md5file):
par_dir, base_dir = os.path.split(src_dir.rstrip('/'))
back_name = '%s_incr_%s.tar.gz' % (base_dir, time.strftime('%Y%m%d'))
full_name = os.path.join(dst_dir, back_name)
md5new = {} for path, folders, files in os.walk(src_dir):
for fname in files:
full_path = os.path.join(path, fname)
md5new[full_path] = md5check(full_path) with open(md5file) as fobj:
md5old = p.load(fobj) with open(md5file, 'w') as fobj:
p.dump(md5new, fobj) tar = tarfile.open(full_name, 'w:gz')
for key in md5new:
if md5old.get(key) != md5new[key]:
tar.add(key)
tar.close()if __name__ == '__main__':
src_dir = '/Users/xkops/gxb/'
dst_dir = '/tmp/'
md5file = '/Users/xkops/md5.data'
if time.strftime('%a') == 'Mon':
full_backup(src_dir, dst_dir, md5file)
else:
incr_backup(src_dir, dst_dir, md5file)