def ReadBlackList(path):
  """Read a blacklist of forbidden directories and files.

  Ignore lines starting with a # so we can comment the datafile.

  Args:
    path: file to load the blacklist from.
  Returns:
    dictionary of path:True mappings
  """
  blacklist_file = open(path, 'r')
  catalog = []
  for entry in blacklist_file:
    if not entry or entry[:1] == '#':
      pass   # ignore comment and empty lines in blacklist file
    else:
      catalog.append(entry.strip())
  return catalog