title: How to clear string in a specific coordinate range in ncurses?
body: <p>So far I've learnt how to use  window.move(y, x) and window.clrtoeol() to clear content at a specific line or from any start point to the end of that line.</p>
  
  <p>I'm designing a game similar to tetris, but the 'block' falls down will cause a collision, then the certain area will be cleared, depend on the block length. So I need to know how to remove strings in a specific coordinate range. For example: </p>
  
  <pre><code>import curses
  
  stdscr = curses.initscr()
  
  for y in range(9,20):
      for x in range(9,20):
          stdscr.addstr(y,x,'#')
  
  stdscr.refresh()
  </code></pre>
  
  <p>the above code make a square with string '#'.
  <strong>How could I clear the content start from (10,10) and end at(10,20)?</strong></p>