Chapter9ZipBackup.py

#! usr/bin/env python3
#Chapter 9 ZIP Backup - Copies and entire folder and contents into
#ZIP file whose filename increments.

import zipfile, os

def backupToZip(folder):
    #Backup the entire contents of the "folder" into a ZIP file.

    folder = os.path.abspath(folder) #make sure folder is absolute

    #Figure out the filename this code should use based on
    #what files already exist.
    number = 1
    while True:
        zipFilename = os.path.basename(folder) + '_' + str(number) + '.zip'
        if not os.path.exists(zipFilename):
            break
        number = number + 1

    #Create the ZIP file.
    print ('Creating %s...' % (zipFilename))
    backupZip = zipfile.ZipFile (zipFilename, 'w')

    #Walk the entire folder tree and compress the files in each folder.
    for foldername, subfolders, filenames in os.walk(folder):
        print ('Adding files in %s...' % (foldername))
        #Add the current folder to the ZIP file.
        backupZip.write (foldername)
        #Add all the files in this folder to the ZIP file.
        for filename in filenames:
            newBase = os.path.basename(folder) + '_'
            if filename.startswith(newBase) and filename.endswith('.zip')
                continue #don't bacuk the backup ZIP files
            backupZip.write (os.path.join(foldername, filename))
    backupZip.close()
    print ('Done.')

backupToZip('/Users/spencercorwin/Downloads')