def test_gc_content():
    assert (DNA('ATTTATGGCC').gc_content == 0.4)
    assert (DNA('AGGTATGGCC').gc_content == 0.6)
    assert (DNA('ATAT').gc_content == 0)
def test_gc_content():
    assert (DNA('ATTTATGGCC').gc_content == 0.4)
    assert (DNA('AGGTATGGCC').gc_content == 0.6)
    assert (DNA('ATAT').gc_content == 0)