Python USES 7z to extract software to backup file script sharing

Required installation:

1. The Python
2.7z decompression software

Backup_2. Py

# Filename: backup_2.py
'''Backup files.
    Version: V2, based on Python 3.3
    Usage: backup.py -s:"dir1|dir2|..." -t:"target_dir" [-c:"comment"]
        -s: The source directories.
        -t: The target directory.
        -c: Optional, any comment.
    Examples: 
        backup.py -s:"c:\src\F1|c:\src\F2|c:\src\F 3" -t:"c:\backup"
        backup.py -s:"c:\src\F 3" -t:"c:\backup" -c:"For sample"'''
import os
import sys
import time
# Read sys.argv
print(sys.argv)
if len(sys.argv) < 2:
    print(__doc__)
    sys.exit()
source=[]
target_dir=''
comment=''
for arg in sys.argv:
    if arg.startswith('-s:'):
        source=arg[3:].split('|')
        print(source)
    elif arg.startswith('-t:'):
        target_dir=arg[3:]+os.sep
        print(target_dir)
    elif arg.startswith('-c:'):
        comment=arg[3:]
        print(comment)
for i in range(0, len(source)):
    source[i] = """ + source[i] + """
    print(source[i])
# Make the file name with the time and comment
today=target_dir+time.strftime('%Y%m%d')
now=time.strftime('%H%M%S')
if len(comment)==0: # check if a comment was entered
    target=today+os.sep+now+'.7z'
else:
    target=today+os.sep+now+'_'+
            comment.replace(' ','_')+'.7z'
# Create the subdirectory by day
if not os.path.exists(today):
    os.mkdir(today) # make directory
    print('Successfully created directory',today)
# zip command
zip_command="7z a %s %s" %(target,' '.join(source))
print(zip_command)
# Run the backup
if os.system(zip_command)==0:
    print('Successful backup to',target)
else:
    print('Backup FAILED')