def get_ftp_dir(abspath: str) -> str:
    """
    Returns path within ftp site

    Parameters
    ----------
    abspath
        The full ftp url

    Returns
    -------
    str
        The relative path within the ftp site

    Examples
    --------
    >>> abspath = 'ftp://ftp.ncbi.nlm.nih.gov/genomes/all/GCF/901/128/'\
                  '725/GCF_900128725.1_BCifornacula_v1.0'
    >>> get_ftp_dir(abspath)
    'genomes/all/GCF/900/128/725/GCF_900128725.1_BCifornacula_v1.0'

    """
    return '/' + '/'.join(abspath.split('/')[3:])