一個Python備份腳本

編寫一個Python腳本，實現為重要的文件或文件夾在指定的目錄下創建備份。

[設計思路]
[1] 將需要備份的文件和目錄由一個列表指定，通過傳入參數獲得并保存到列表中。
[2] 備份應該保存在主備份目錄中。
[3] 將文件備份成一個壓縮文件。
[4] 每一次備份都根據當前的日期在主備份目錄中創建一個子文件夾，而所備份的文件命名為當期的時間保存在這個子文件夾中。
[5] 壓縮命令由本地用戶決定。可以使用任何本地的存檔壓縮命令，只要它有命令行界面就可以了，那樣就可以從腳本中傳遞參數給它。

[參考]
[1] A Byte of Python, 2005
[2] Python Manuals 2.6

    #! /usr/bin/python


# Filename: backup_ver1.py  
# 2010-7-12 wcdj  
import os  
import time  
import sys  
# 1, The files and directories to be backed up are specified in a list  
# source = ['/home/wcdj/my_prog', '/home/wcdj/local_installed']  
# The following information is the debug used  
print '--------------------------------'  
source=[]  
print 'The command line arguments are: '  
for i in sys.argv:  
    print i  
    if i == sys.argv[0]:  
        continue  
    source.append(i)  
print source  
print '--------------------------------'  
# check input, if error app exit  
if len(source) == 0:  
    print '''''You should input the files or directories, like 
python backup_ver1.py /home/wcdj/myfile /home/wcdj/mydir ...'''  
    exit()  
else:  
    print 'Some files or directorier will be saved into .tar.gz format: '  
    print source  
# If you are using Windows, use   
# source=[r'c:/Documents', r'd:/work'] or   
# source=['c://Documents', 'd://work'] or   
# something like that  
# 2, The backup must be stored in a main backup directory  
# Remember to change this to what you will be using  
target_dir = '/home/wcdj/backup/'  
# 3, The files are backed up into a tar file  
# 4, The name of subdirectory and tar file  
today = target_dir + time.strftime('%Y%m%d')  
now = time.strftime('%H%M%S')  
# Take a comment from the user to create the name of the tar file  
comment = raw_input('Enter a comment: ')  
if len(comment) == 0:# check if a comment was entered  
    target = today + os.sep + now + '.tar.gz'  
else:  
    target = today + os.sep + now + '_' + /  
    comment.replace(' ', '_') + '.tar.gz'  
#Create the subdirectory if it isn't already there  
if not os.path.exists(today):  
    os.mkdir(today)# make directory  
    print 'Successfully created directory', today  
# 5, We use the tar command(in Unix/Linux) to put the files in a tgz archive  
tar_command = "tar -zcf %s %s" % (target, ' '.join(source))  
# Run the backup  
if os.system(tar_command) == 0:  
    print 'Successful backup to', target  
else:  
    print 'Backup failed'  
# end  </pre>