Jupyter notebook toggle code-cells on/off

notebook_toggle_code_onoff

from IPython.display import HTML

HTML('''<script>
  code_show=true;
  function code_toggle() {
    if (code_show){
      $('div.input').hide();
    } else {
      $('div.input').show();
    }
    code_show = !code_show
  }
  $( document ).ready(code_toggle);
</script>
<form action="javascript:code_toggle()"><input type="submit" value="Toggle code on/off"></form>''')