def distance_between_pts(a=(0.0, 0.0), b=(0.0, 0.0)):
    '''Return the distance between two points on N dimensions (Euclidean distance).
    '''
    assert isinstance(a, tuple)
    assert isinstance(b, tuple)
    l_pt = len(a)
    assert l_pt > 1
    assert l_pt == len(b)
    for i in a:
        assert isinstance(i, float)
    for i in b:
        assert isinstance(i, float)

    return sqrt(sum([(b[i] - a[i])**2 for i in range(l_pt)]))