def _get_version_info():
    """
    Return astropy and photutils versions.

    Returns
    -------
    result : str
        The astropy and photutils versions.
    """
    from astropy import __version__
    astropy_version = __version__
    from photutils import __version__
    photutils_version = __version__
    return 'astropy: {0}, photutils: {1}'.format(astropy_version,
        photutils_version)
