   [--, 4, 5],
        [6, 7, 8]],
  mask=[[ True, False, False],
        [ True, False, False],
        [False, False, False]],
  fill_value=999999)

>>> np.ma.compress_rowcols(x)
array([[7, 8]])
>>> np.ma.compress_rowcols(x, 0)
array([[6, 7, 8]])
>>> np.ma.compress_rowcols(x, 1)
array([[1, 2],
       [4, 5],
       [7, 8]])

rö