numpy.``c_ =
    Translates slice objects to concatenation along the second axis.
    This is short-hand for np.r_['-1,2,0', index expression], which is useful because of its common occurrence. In particular, arrays will be stacked along their last axis after being upgraded to at least 2-D with 1’s post-pended to the shape (column vectors made out of 1-D arrays).
    See also
    column_stackStack 1-D arrays as columns into a 2-D array.r_For more detailed documentation.
    Examples
    >>>
    >>> np.c[np.array([1,2,3]), np.array([4,5,6])]
    array([[1, 4],
    [2, 5],
    [3, 6]])
    >>> np.c
    [np.array([[1,2,3]]), 0, 0, np.array([[4,5,6]])]
    array([[1, 2, 3, …, 4, 5, 6]])