      "\n",
      "def main():\n",
      "    test = TestQuickSort()\n",
      "    test.test_quick_sort(quick_sort)\n",
      "    try:\n",
      "        test.test_quick_sort(quick_sort_alt)\n",
      "    except NameError:\n",
      "        # Alternate solutions are only defined\n",
      "        # in the solutions file\n",
      "        pass\n",
      "\n",
      "\n",
      "if __name__ == '__main__':\n",
      "    main()"
     ]
 
</s>
      "\n",
      "def main():\n",
      "    test = TestQuickSort()\n",
      "    test.test_quick_sort(quick_sort)\n",






      "\n",
      "\n",
      "if __name__ == '__main__':\n",
      "    main()"
     ]
keep keep keep keep replace replace replace replace replace replace keep keep keep keep keep
 Polish quicksort challenge and solution

Add None input test case.  Remove difficult to read 'Pythonic' solution.  Update space complexity discussion.
sorting_searching/quick_sort/quick_sort_solution.ipynb