def normalise_folder_path(path):
    """
    Normalise a folder path

    Normalise folder paths so that they are always of the
    form

    /path/to/folder

    i.e a single leading slash with no trailing slash

    Arguments:
      path (str): path for a data library folder

    Returns:
      str: normalised folder path.

    """
    return  '/'+'/'.join([x for x in path.split('/') if x != ''])