test_nditer.py 文件源码

def test_iter_nested_iters_flip_axes():
    # Test nested iteration with negative axes
    a = arange(12).reshape(2, 3, 2)[::-1, ::-1, ::-1]

    # In 'K' order (default), the axes all get flipped
    i, j = np.nested_iters(a, [[0], [1, 2]])
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[0, 1, 2, 3, 4, 5], [6, 7, 8, 9, 10, 11]])

    i, j = np.nested_iters(a, [[0, 1], [2]])
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[0, 1], [2, 3], [4, 5], [6, 7], [8, 9], [10, 11]])

    i, j = np.nested_iters(a, [[0, 2], [1]])
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[0, 2, 4], [1, 3, 5], [6, 8, 10], [7, 9, 11]])

    # In 'C' order, flipping axes is disabled
    i, j = np.nested_iters(a, [[0], [1, 2]], order='C')
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[11, 10, 9, 8, 7, 6], [5, 4, 3, 2, 1, 0]])

    i, j = np.nested_iters(a, [[0, 1], [2]], order='C')
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[11, 10], [9, 8], [7, 6], [5, 4], [3, 2], [1, 0]])

    i, j = np.nested_iters(a, [[0, 2], [1]], order='C')
    vals = []
    for x in i:
        vals.append([y for y in j])
    assert_equal(vals, [[11, 9, 7], [10, 8, 6], [5, 3, 1], [4, 2, 0]])