      "def quick_sort(data):\n",
      "    if data is None or len(data) < 2:\n",
      "        return data\n",
      "    left = []\n",
      "    right = []\n",
      "    pivot_index = len(data) // 2\n",
      "    pivot_value = data[pivot_index]\n",
      "\n",
 
</s> remove     "    for i in range(0, len(data)):\n",
    "        if i == pivot_index:\n",
    "            continue\n",
    "        if data[i] < pivot_value:\n",
 </s> add     "    for i in range(len(data)):\n",
    "        if data[i] == pivot_value:\n",
    "            equal.append(data[i])\n",
    "        elif data[i] < pivot_value:\n", </s> remove     "    return left + [pivot_value] + right"
 </s> add     "    return left + equal + right" </s> remove    "version": "3.4.3"
 </s> add    "version": "3.5.0"
    "    equal = []\n",
      "def quick_sort(data):\n",
      "    if data is None or len(data) < 2:\n",
      "        return data\n",
    "    equal = []\n",
      "    left = []\n",
      "    right = []\n",
      "    pivot_index = len(data) // 2\n",
      "    pivot_value = data[pivot_index]\n",
      "\n",
keep keep add keep keep keep keep keep
 Polish quicksort challenge and solution

Update constraints and code. 
sorting_searching/quick_sort/quick_sort_solution.ipynb