Return given point shifted in N dimensions.

def pt_shift(pt=(0.0, 0.0), shift=[0.0, 0.0]):
    '''Return given point shifted in N dimensions.
    '''
    assert isinstance(pt, tuple)
    l_pt = len(pt)
    assert l_pt > 1
    for i in pt:
        assert isinstance(i, float)
    assert isinstance(shift, list)
    l_sh = len(shift)
    assert l_sh == l_pt
    for i in shift:
        assert isinstance(i, float)

    return tuple([pt[i] + shift[i] for i in range(l_pt)])