old_contents: #! python3
  # backupToZip.py - Copies an entire folder and its contents into
  # a ZIP file whose filename increments.
  
  import zipfile, os
  
  def backupToZip(folder):
      # Backup the entire contents of "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 back up the backup ZIP files
              backupZip.write(os.path.join(foldername, filename))
      backupZip.close()
      print('Done.')
  
  
  backupToZip('./delicious')
  
new_contents: #! python3
  # backupToZip.py - Copies an entire folder and its contents into
  # a ZIP file whose filename increments.
  
  import zipfile, os
  
  
  def backupToZip(folder):
      # Backup the entire contents of "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 back up the backup ZIP files
              backupZip.write(os.path.join(foldername, filename))
      backupZip.close()
      print('Done.')
  
  
  backupToZip('./delicious')
  
subject: Update P05_backupToZip: fixed some PEP8 checks