mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
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c24a628329
Update constraints, algorithm discussion, and code.
221 lines
5.2 KiB
Python
221 lines
5.2 KiB
Python
{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"<small><i>This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Challenge Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Implement a binary search tree with an insert method.\n",
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"\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Constraints\n",
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"\n",
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"* Can we insert None values?\n",
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" * No\n",
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"* Can we assume we are working with valid integers?\n",
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" * Yes\n",
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"* Can we assume all left descendents <= n < all right descendents?\n",
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" * Yes\n",
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"* For simplicity, can we use just a Node class without a wrapper Tree class?\n",
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" * Yes\n",
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"* Do we have to keep track of the parent nodes?\n",
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" * This is optional\n",
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"* Can we assume this fits in memory?\n",
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" * Yes"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"### Insert\n",
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"\n",
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"Insert will be tested through the following traversal:\n",
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"\n",
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"### In-Order Traversal\n",
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"\n",
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"* 5, 2, 8, 1, 3 -> 1, 2, 3, 5, 8\n",
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"* 1, 2, 3, 4, 5 -> 1, 2, 3, 4, 5\n",
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"\n",
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"If the `root` input is `None`, return a tree with the only element being the new root node.\n",
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"\n",
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"You do not have to code the in-order traversal, it is part of the unit test."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Algorithm\n",
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"\n",
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"Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/bst/bst_solution.ipynb). If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"class Node(object):\n",
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"\n",
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" def __init__(self, data):\n",
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" # TODO: Implement me\n",
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" pass\n",
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"\n",
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"\n",
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"def insert(root, data):\n",
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" # TODO: Implement me\n",
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" pass"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Unit Test"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"**The following unit test is expected to fail until you solve the challenge.**"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": true
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},
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"outputs": [],
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"source": [
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"%run dfs.py"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": true
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},
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"outputs": [],
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"source": [
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"%run ../utils/results.py"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"# %load test_bst.py\n",
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"from nose.tools import assert_equal\n",
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"\n",
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"\n",
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"class TestTree(object):\n",
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"\n",
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" def __init__(self):\n",
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" self.results = Results()\n",
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"\n",
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" def test_tree(self):\n",
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" node = Node(5)\n",
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" insert(node, 2)\n",
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" insert(node, 8)\n",
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" insert(node, 1)\n",
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" insert(node, 3)\n",
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" in_order_traversal(node, self.results.add_result)\n",
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" assert_equal(str(self.results), '[1, 2, 3, 5, 8]')\n",
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" self.results.clear_results()\n",
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"\n",
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" node = insert(None, 1)\n",
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" insert(node, 2)\n",
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" insert(node, 3)\n",
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" insert(node, 4)\n",
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" insert(node, 5)\n",
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" in_order_traversal(node, self.results.add_result)\n",
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" assert_equal(str(self.results), '[1, 2, 3, 4, 5]')\n",
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"\n",
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" print('Success: test_tree')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestTree()\n",
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" test.test_tree()\n",
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"\n",
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"\n",
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"if __name__ == '__main__':\n",
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" main()"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Solution Notebook\n",
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"\n",
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"Review the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/bst/bst_solution.ipynb) for a discussion on algorithms and code solutions."
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.5.0"
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}
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"nbformat": 4,
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"nbformat_minor": 0
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