ver. The default,
         axis=None, will flip over all of the axes of the input array.
         If axis is negative it counts from the last to the first axis.

         If axis is a tuple of ints, flipping is performed on all of the axes
         specified in the tuple.

         .. versionchanged:: 1.15.0
            None and tuples of axes are supported

    Returns
    -------
    out : array_like
        A view of `m` with the entries of axis reversed.  Since a view is
        returned, this operation is done in constant time.

    See Also
    --------
    flipud : Flip an array vertically (axis=0).
    fliplr : Flip an array horizontally (axis=1).

    Notes
    -----
    flip(m, 0) is equivalent to flipud(m).

    flip(m, 1) is equivalent to fliplr(m).

    flip(m, n) corresponds to ``m[...,::-1,...]`` with ``::-1`` at position n.

    flip(m) corresponds to ``m[::-1,::-1,...,::-1]`` with ``::-1`` at all
    positions.

    flip(m, (0, 1)) corresponds to ``m[::-1,::-1,...]`` with ``::-1`` at
    position 0 and position 1.

    Examples
    --------
    >>> A = np.arange(8).reshape((2,2,2))
    >>> A
    array([[[0, 1],
            [2, 3]],
           [[4, 5],
            [6, 7]]])
    >>> np.flip(A, 0)
    array([[[4, 5],
            [6, 7]],
           [[0, 1],
            [2, 3]]])
    >>> np.flip(A, 1)
    array([[[2, 3],
            [0, 1]],
           [[6, 7],
            [4, 5]]])
    >>> np.flip(A)
    array([[[7, 6],
            [5, 4]],
           [[3, 2],
            [1, 0]]])
    >>> np.flip(A, (0, 2))
    array([[[5, 4],
            [7, 6]],
           [[1, 0],
            [3, 2]]])
    >>> A = np.random.randn(3,4,5)
    >>> np.all(np.flip(A,2) == A[:,:,::-1,...])
    True
    r¸