Download gaf, gpad, or gpi from http://current.geneontology.org/annotations/

def dnld_annotation(assc_file, prt=sys.stdout):
    """Download gaf, gpad, or gpi from http://current.geneontology.org/annotations/"""
    if not os.path.isfile(assc_file):
        # assc_http = "http://geneontology.org/gene-associations/"
        assc_http = "http://current.geneontology.org/annotations/"
        _, assc_base = os.path.split(assc_file)
        src = os.path.join(assc_http, "{ASSC}.gz".format(ASSC=assc_base))
        dnld_file(src, assc_file, prt, loading_bar=None)