How to use the goatools.base.download_go_basic_obo function in goatools

def test_i147_all_taxids():
    """Work with all taxids using Gene2GoReader"""
    # 1. Download Ontologies and Associations
    # 1a. Download Ontologies, if necessary
    #     Get http://geneontology.org/ontology/go-basic.obo
    download_go_basic_obo()

    # 1b. Download Associations, if necessary
    #     Get ftp://ftp.ncbi.nlm.nih.gov/gene/DATA/gene2go.gz
    fin_gene2go = download_ncbi_associations()

    # 2. Load Ontologies, Associations and Background gene set
    # 2a. Load Ontologies
    godag = GODag("go-basic.obo")

    # 2b. Load Associations for all species
    #     Read NCBI's gene2go. Store annotations in a list of namedtuples
    objanno_all = Gene2GoReader(fin_gene2go, godag=godag, taxids=True)
    objanno_mmu = Gene2GoReader(fin_gene2go, godag=godag, taxids=[10090])
    objanno_mmuhsa = Gene2GoReader(fin_gene2go, godag=godag, taxids=[10090, 9606])

    # Get associations

def get_genes_cell_cycle(taxid=9606, log=sys.stdout):
    """Test GOEA with local multipletest correction methods for cell cycle."""
    # Download ontologies and annotations, if necessary
    fin_go_obo = os.path.join(os.getcwd(), "go-basic.obo")
    download_go_basic_obo(fin_go_obo, loading_bar=None)
    # Because get_assoc_ncbi_taxids returns id2gos, we will opt to
    # use the (optional) multi-level dictionary separate associations by taxid
    # taxid2asscs contains both GO2IDs and ID2GOs.
    taxid2asscs = defaultdict(lambda: defaultdict(lambda: defaultdict(set)))
    get_assoc_ncbi_taxids([taxid], taxid2asscs=taxid2asscs, loading_bar=None)

    # Initialize GO-search helper object with obo and annotations(go2items)
    srch = GoSearch(fin_go_obo, go2items=taxid2asscs[taxid]['GO2IDs'])
    # Compile search pattern for 'cell cycle'
    cell_cycle = re.compile(r'cell cycle', flags=re.IGNORECASE)
    # Find ALL GOs that have 'cell cycle'. Store results in file.
    fout_allgos = "cell_cycle_gos_{TAXID}.log".format(TAXID=taxid)
    with open(fout_allgos, "w") as prt:
        # Search for 'cell cycle' in GO terms
        gos_cc_all = srch.get_matching_gos(cell_cycle, prt=prt)
        # Researcher carefully reviews GO results and finds GO:0005764(lysosome)

def test_go_print(prt=sys.stdout):
    """Test that all GO Terms can be printed, even if level/depth are not assigned."""
    prt_pypath(prt)
    file_obo = os.path.join(os.getcwd(), "go-basic.obo")
    obo_file = download_go_basic_obo(file_obo, prt=prt, loading_bar=None)
    reader = goatools.obo_parser.OBOReader(obo_file)
    go_terms = list(reader)
    prt.write("Python Version: {VER}\n\n".format(VER=sys.version))
    prt.write("\nOBOReader: {OBJ}\n\n".format(OBJ=reader))
    prt.write("format-version: {VER}\n".format(VER=reader.format_version))
    prt.write("data-version: {VER}\n\n".format(VER=reader.data_version))
    prt.write("Found {N} GO Records:\n".format(N=len(go_terms)))
    for idx, go_rec in enumerate(go_terms):
        prt.write("{I:>7,} {RECORD}\n".format(I=idx, RECORD=go_rec))

def dnld_ontology(filename):
    """Test downloading of ontologies."""
    # download_go_basic_obo(filename, loading_bar=None)
    os.system("rm -f {FILE}".format(FILE=filename))
    download_go_basic_obo(filename, loading_bar=None)
    download_go_basic_obo(filename, loading_bar=None)
    assert os.path.isfile(filename), "FILE({F}) EXPECTED TO EXIST".format(F=filename)

def _init_dnld_dag(self):
        """If dag does not exist, download it."""
        if not os.path.exists(self.obo):
            download_go_basic_obo(self.obo, loading_bar=None)