Add new mission solution for 234

Mission234Solutions.ipynb

@@ -0,0 +1,131 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 39,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "import pickle\n",
+    "from btree import Node, BTree, NodeKey\n",
+    "\n",
+    "class DQKV(BTree):\n",
+    "    def __init__(self, type_, values=None):\n",
+    "        self.type = type_\n",
+    "        super().__init__(10)\n",
+    "\n",
+    "    def get(self, key):\n",
+    "        value = self.search(self.root, key)\n",
+    "        if value is None:\n",
+    "            raise KeyError('There is no value for key \"{}\"'.format(key))\n",
+    "        return value\n",
+    "    \n",
+    "    def set(self, key, value):\n",
+    "        if value is None:\n",
+    "            raise ValueError('Cannot store None values')\n",
+    "        if not isinstance(key, self.type):\n",
+    "            raise KeyError('Key must be of type {}'.format(self.type))\n",
+    "        exists = self.search(self.root, key)\n",
+    "        if exists is not None:\n",
+    "            raise ValueError('Cannot store duplicate key values')\n",
+    "            \n",
+    "        node = NodeKey(key, value)\n",
+    "        self.insert(node)\n",
+    "    \n",
+    "    def range_query(self, interval, inclusive=False):\n",
+    "        if not isinstance(interval, (list, tuple)) and len(interval) != 2:\n",
+    "            raise ValueError('The first argument must be a list or tuple of length 2')\n",
+    "        \n",
+    "        lower, upper = interval\n",
+    "        if lower is None:\n",
+    "            return self.less_than(self.root, upper, inclusive=inclusive)\n",
+    "        return self.greater_than(self.root, lower, upper_bound=upper, inclusive=inclusive)\n",
+    "    \n",
+    "    def save(self, filename):\n",
+    "        filename = filename + '.dqdb'\n",
+    "        with open(filename, 'wb') as f:\n",
+    "            pickle.dump(self, f)\n",
+    "            return True\n",
+    "        return False\n",
+    "    \n",
+    "    def load_from_dict(self, dictionary):\n",
+    "        for key, value in dictionary.items():\n",
+    "            self.set(key, value)\n",
+    "    \n",
+    "    @staticmethod\n",
+    "    def load(filename):\n",
+    "        filename = filename + '.dqdb'\n",
+    "        with open(filename, 'rb') as f:\n",
+    "            return pickle.load(f)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 45,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[<NodeKey: (2, world)>]\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 45,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "dq = DQKV(int)\n",
+    "dq.set(1, 'hello')\n",
+    "dq.set(2, 'world')\n",
+    "dq.set(3, 'this')\n",
+    "dq.set(4, 'is')\n",
+    "print(dq.range_query([1,3]))\n",
+    "\n",
+    "dq.save('sample_store')\n",
+    "dqkv = DQKV.load('sample_store')\n",
+    "\n",
+    "print(dqkv.range_query([1,3]))\n",
+    "additional_keys = {\n",
+    "    5: 'a',\n",
+    "    6: 'simple',\n",
+    "    7: 'kv store'\n",
+    "}\n",
+    "dqkv.load_from_dict(additional_keys)\n",
+    "print(dqkv.range_query([4,8]))\n",
+    "print(dqkv.get(5))"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}