      "### Get\n",
      "\n",
      "* Get hash index for lookup\n",
      "* If key exists, return value\n",
      "* Else, return NULL\n",
      "\n",
      "Complexity:\n",
      "* Time: O(1) average and best, O(n) worst\n",
      "* Space: O(1)\n",
      "\n",
 
</s> remove     "* If stack is empty, return NULL\n",
 </s> add     "* If stack is empty, return None\n", </s> remove     "* If stack is empty, return NULL\n",
 </s> add     "* If stack is empty, return None\n", </s> remove     "* If data we are finding is NULL, return\n",
 </s> add     "* If data we are finding is None, return\n", </s> remove     "* If the data we are inserting is NULL, return\n",
 </s> add     "* If the data we are inserting is None, return\n", </s> remove     "* If data we are deleting is NULL, return\n",
 </s> add     "* If data we are deleting is None, return\n",
    "* Else, return None\n",
      "### Get\n",
      "\n",
      "* Get hash index for lookup\n",
      "* If key exists, return value\n",
    "* Else, return None\n",
      "\n",
      "Complexity:\n",
      "* Time: O(1) average and best, O(n) worst\n",
      "* Space: O(1)\n",
      "\n",
keep keep keep keep replace keep keep keep keep keep
 Changed discussions of NULL to None to be more Pythonic. 
arrays_strings/hash_map/hash_map_solution.ipynb