Converts the absolute path to a saltclass file back to the dotted notation.

    .. code-block:: python

       print(get_class_from_file('/srv/saltclass/classes/services/nginx/init.yml', '/srv/saltclass'))
       # services.nginx

    :param str _file: Absolute path to file
    :param str saltclass_path: Root to saltclass storage
    :return: class name in dotted notation
    :rtype: str

def get_class_from_file(_file, saltclass_path):
    '''
    Converts the absolute path to a saltclass file back to the dotted notation.

    .. code-block:: python

       print(get_class_from_file('/srv/saltclass/classes/services/nginx/init.yml', '/srv/saltclass'))
       # services.nginx

    :param str _file: Absolute path to file
    :param str saltclass_path: Root to saltclass storage
    :return: class name in dotted notation
    :rtype: str
    '''
    # remove classes path prefix
    _file = _file[len(os.path.join(saltclass_path, 'classes')) + len(os.sep):]
    # remove .yml extension
    _file = _file[:-4]
    # revert to dotted notation
    _file = _file.replace(os.sep, '.')
    # remove tailing init
    if _file.endswith('.init'):
        _file = _file[:-5]
    return _file