Python's curses module does not refresh pad until first character received

I have the following code that allows you to scroll up and down a pad of text. Each time you scroll (i.e. handle a user input) the pad updates as expected. However, before the first key is pressed nothing is shown, despite that I'm calling pad.refresh() just as I do after each user input.

My code looks like this :

def main(self,stdscr):

    x,y = 20,150 # size of the window
    u,a = 10,20 # where to place window - up,across
    pad = curses.newpad(20,150) # nlines, ncols
    pad_pos = 0
    exit = False

    pad.addstr(0,0,str(self.all_results))

    while not exit:
        pad.addstr(0,0,str(self.format_results()))
        ++ stdscr.refresh()
        pad.refresh(pad_pos,10, u,a, x,y)

        -- cmd = stdscr.getch()
        ++ cmd = pad.getch()

        stdscr.nodelay(1)

        + pad.getch() - caused the screen not to update
        + stdscr.refresh() - no change

        if cmd != -1:
            + pad.getch() - - caused the screen not to update
            if  cmd == curses.KEY_DOWN:
                if pad_pos < 3:
                    pad_pos += 1
                try:
                    pad.refresh(pad_pos,0, u,a, x,y)
                except curses.error:
                    pass
            elif cmd == curses.KEY_UP:
                if pad_pos != 0:
                    pad_pos -= 1
                try:
                    pad.refresh(pad_pos,0, u,a, x,y)
                except curses.error:
                    pass

Edit : changes shown within code as to what has been tried (+,++,--)

Try calling stdscr.nodelay(1) BEFORE you hang up on stdscr.getch().