def _get_resource_loc(model_id):
    """returns folder_id and file_id needed to find location of edited photo"""
    """ and live photos for version <= Photos 4.0 """
    # determine folder where Photos stores edited version
    # edited images are stored in:
    # Photos Library.photoslibrary/resources/media/version/XX/00/fullsizeoutput_Y.jpeg
    # where XX and Y are computed based on RKModelResources.modelId

    # file_id (Y in above example) is hex representation of model_id without leading 0x
    file_id = hex_id = hex(model_id)[2:]

    # folder_id (XX) in above example if first two chars of model_id converted to hex
    # and left padded with zeros if < 4 digits
    folder_id = hex_id.zfill(4)[0:2]

    return folder_id, file_id