python脚本实现文件备份

本脚本通过判断是否为周一来执行完全备份或增量备份,需提前放到计划任务中每天执行,实现周一完全备份,之后每天增量备份的功能.具体代码实现如下

#!/root/bin/python
from time import strftime
import os
import tarfile
import hashlib
import pickle

def check_md5(fname):
    m = hashlib.md5()
    with open(fname,'rb') as fobj:
        while 1:
            data = fobj.read(4096)
            if not data:
                break
            m.update(data)
    return m.hexdigest()

def full_backup(src,dst,md5file):
    fname = os.path.basename(src)
    fname = '%s_full_%s.tar.gz'% (fname,strftime('%Y%m%d'))
    fname = os.path.join(dst,fname)

    tar = tarfile.open(fname,'w:gz')
    tar.add(src)
    tar.close()

    md5dict = {}
    for path,folders,files in os.walk(src):
        for file in files:
            key = os.path.join(path,file)
            md5dict[key] = check_md5(key)

    with open(md5file,'wb') as fobj:
        pickle.dump(md5dict,fobj)


def incr_backup(src,dst,md5file):
    fname = os.path.basename(src)
    fname = '%s_incr_%s.tar.gz'% (fname,strftime('%Y%m%d'))
    fname = os.path.join(dst,fname)

    md5dict = {}
    for path,folders,files in os.walk(src):
        for file in files:
            key = os.path.join(path,file)
            md5dict[key] = check_md5(key)

    with open(md5file, 'rb') as fobj:
        old_md5 = pickle.load(fobj)

    tar = tarfile.open(fname, 'w:gz')
    for key in md5dict:
        if old_md5.get(key) != md5dict[key]:
            tar.add(key)
    tar.close()
    with open(md5file,'wb') as fobj:
        pickle.dump(md5dict,fobj)


if __name__ == '__main__':
    src = '/tmp/demo/security'
    dst = '/tmp/demo/backup'
    md5file = '/tmp/demo/backup/md5.data'
    if strftime('%a') == 'Mon':
        full_backup(src,dst,md5file)
    else:
        incr_backup(src,dst,md5file)