human
I wrote the below code

    if pad:
        patch_list = _pad_patch_list(patch_list)
    patch_list = _preproecss_patch_list(patch_list)
    if (lclick_cb is not None):
        viz = True
    (ph, pw) = patch_list.shape[1:3]
    canvas = Canvas(ph, pw, nr_row, nr_col, patch_list.shape[(-1)], border, bgcolor)
    if (lclick_cb is not None):
        def lclick_callback(img, x, y):
            idx = canvas.get_patchid_from_coord(x, y)
            lclick_cb(patch_list[idx], idx)
    else:
        lclick_callback = None
    canvas.draw_patches(patch_list)
    if viz:
        interactive_imshow(canvas.canvas, lclick_cb=lclick_callback)
    return canvas.canvas

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def stack_patches(patch_list, nr_row, nr_col, border=None, pad=False, bgcolor=255, viz=False, lclick_cb=None):