{
  "nbformat": 4,
  "nbformat_minor": 0,
  "metadata": {
    "colab": {
      "name": "Example.ipynb",
      "provenance": [],
      "collapsed_sections": []
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    }
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "SDtiowU30ygW"
      },
      "source": [
        "# Introducing the Notebook\n",
        "\n",
        "Google colab is a version of the 'jupyter' notebook. This is an example notebook. Edit this note book to learn how the notebook system works. \n"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "TqNQ66jLePXa"
      },
      "source": [
        "# Cells in the Notebook\n",
        "\n",
        "The notebook is a sequence if cells. \n",
        "* A cell (such as this one) can contain text. This makes a data analysis notebook a readable document. \n",
        "* Text is formatted using *markdown*\n",
        "* Other cells in the notebook contain code. The analysis document becomes executable.\n",
        "\n",
        "The next cell contaions code. Run it!"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "KFw99xYk1PZb"
      },
      "source": [
        "x = 1 + 2\n",
        "x"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "PkHcjHxAfH9I"
      },
      "source": [
        "Subsequent cells can use the variable introduced earlier."
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "IFa80aLG1nks"
      },
      "source": [
        "x ** 2"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "cDVAlToIfQsd"
      },
      "source": [
        "Writing an expression causes the value to echoed. We can use the notebook as a calculator"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "3 ** 4 ** 5"
      ],
      "metadata": {
        "id": "VdW6cna8NDnK"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "FVQhFQYq2okd"
      },
      "source": [
        "# Problems to Watch Out for When Editing\n",
        "\n",
        "You are free to run cells out of order, changing and rerunning earlier parts of your program. However, this can be confusing:\n",
        "\n",
        "* There is a global environment of values and variables\n",
        "* A variable continues to exist even if you remove the code that created it \n",
        "\n",
        "**Recommendation:** periodically rerun the whole notebook in order\n"
      ]
    }
  ]
}