Example to page through dict

get_prev_next.ipynb

{
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   "cell_type": "code",
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   "source": [
    "d = {3: 'something', 2: 'something else', 1: 'starting'}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 2, 3]\n"
     ]
    }
   ],
   "source": [
    "key_list = sorted(d.keys())\n",
    "print(key_list)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Current value for index 0:\n",
      "    \"starting\"\n",
      "Previous value for index 0:\n",
      "    \"None\"\n",
      "Next value for index 0:\n",
      "    \"something else\"\n",
      "Current value for index 1:\n",
      "    \"something else\"\n",
      "Previous value for index 1:\n",
      "    \"starting\"\n",
      "Next value for index 1:\n",
      "    \"something\"\n",
      "Current value for index 2:\n",
      "    \"something\"\n",
      "Previous value for index 2:\n",
      "    \"something else\"\n",
      "Next value for index 2:\n",
      "    \"None\"\n"
     ]
    }
   ],
   "source": [
    "for i, key in enumerate(key_list):\n",
    "    print('Current value for index {}:'.format(i))\n",
    "    current_value = d[key_list[i]]\n",
    "    print('    \"{}\"'.format(current_value))\n",
    "\n",
    "    print('Previous value for index {}:'.format(i))\n",
    "    previous_index = i - 1\n",
    "    if previous_index < 0:\n",
    "        previous_index = None\n",
    "    try:\n",
    "        previous_value = d[key_list[previous_index]]\n",
    "    except TypeError:\n",
    "        previous_value = None\n",
    "    print('    \"{}\"'.format(previous_value))\n",
    "    \n",
    "    print('Next value for index {}:'.format(i))\n",
    "    try:\n",
    "        next_value = d[key_list[i + 1]]\n",
    "    except IndexError:\n",
    "        next_value = None\n",
    "    print('    \"{}\"'.format(next_value))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
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