code: def ensure_directory_exists(directory):
    '''Ensures `directory` exists. May make `directory` and intermediate dirs.
    Raises RuntimeError if `directory` is a file.
    '''
    if not os.path.exists(directory):
      os.makedirs(directory)
    elif os.path.isfile(directory):
      raise RuntimeError('Path %s is a file, not a directory.' % directoryf ensure_directory_exists(directory):
    '''Ensures `directory` exists. May make `directory` and intermediate dirs.
    Raises RuntimeError if `directory` is a file.
    '''
    if not os.path.exists(directory):
      os.makedirs(directory)
    elif os.path.isfile(directory):
      raise RuntimeError('Path %s is a file, not a directory.' % directory)
docs: Ensures `directory` exists. May make `directory` and intermediate dirs.
    Raises RuntimeError if `directory` is a file.