{
  "nbformat": 4,
  "nbformat_minor": 0,
  "metadata": {
    "colab": {
      "name": "CPSC217_5Decisions.ipynb",
      "provenance": [],
      "collapsed_sections": []
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    }
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Dap8bd9lwxVG"
      },
      "source": [
        "# Topic 5: Decisions: Booleans"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "FM8AXGw3x2v9"
      },
      "source": [
        "## Booleans"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "ewBQdM0-xYJ8"
      },
      "source": [
        "We can store the idea of true of false"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "ZL9Ifd0dxasd"
      },
      "source": [
        "x = True\n",
        "y = False\n",
        "print(type(x))\n",
        "print(type(y))"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "32dZxi-mx4zV"
      },
      "source": [
        "## Relational operators"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "y4GIPz-mxdEd"
      },
      "source": [
        "We can get these also from relating things (Relational operators)"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "0wS-WvLwxfyt"
      },
      "source": [
        "3 < 5"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "X678DlCCxhPM"
      },
      "source": [
        "5 > 3"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "sbEM0MEVxiLN"
      },
      "source": [
        "3 == 3"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "bQy9F376xjC9"
      },
      "source": [
        "5 <= 5"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "1de75eRqxkC1"
      },
      "source": [
        "3 >= 4"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "tH3-S0DZxoL1"
      },
      "source": [
        "#Not the same =/=\n",
        "#More shared with other languages\n",
        "5 != 3"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "71G4Zv1jxyPc"
      },
      "source": [
        "x = 1.0\n",
        "y = 2.0\n",
        "c = (x <= y)\n",
        "print (type(c))\n",
        "print(c)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "t3jiYsIw3iN0"
      },
      "source": [
        "print(int(True))\n",
        "print(int(False))"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "CEhsLmEOx-pt"
      },
      "source": [
        "## Boolean operators"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "dJo_FBKIx_wF"
      },
      "source": [
        "We can combine things that are already boolean"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "6p1cRtrmyDuW"
      },
      "source": [
        "a = True\n",
        "b = True\n",
        "c = False"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "2CMChlyfyJSN"
      },
      "source": [
        "a and b"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "zUAGbXlQyONV"
      },
      "source": [
        "a and c"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "IgR-PbEcyPeW"
      },
      "source": [
        "a or c"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "Hrk6ie91ySZV"
      },
      "source": [
        "not a"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "tPJpixkYyU4d"
      },
      "source": [
        "## Precedence"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "PZQfWcgcyrI2"
      },
      "source": [
        "Precedence is for math operators first, then relational, then booleans, and finally assignment to a variable"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "rUYb74y6yWz9"
      },
      "source": [
        "not True and False or True"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "srHL19hoyfOG"
      },
      "source": [
        "((not True) and False) or True"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "u3jw46SryfbF"
      },
      "source": [
        "(not True) and (False or True)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "wwK5CwZMzAVv"
      },
      "source": [
        "Things are always better with brackets"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "wMMtzA7Eyzou"
      },
      "source": [
        "not 6 == 2 * 3 and False or True"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "vZCs-AVGzC1a"
      },
      "source": [
        "((not (6 == (2 * 3))) and False) or True"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "IQCTV4yqzICv"
      },
      "source": [
        "##Truth tables "
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "UaJaRQRm7X9l"
      },
      "source": [
        "a = 1\n",
        "b = 0\n",
        "print(a and b)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "8KRxokSTzRJm"
      },
      "source": [
        "How we write down how a boolean opreator, or expression is evaluated for different inputs"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "eL4JO9N6zQh_"
      },
      "source": [
        "print(\"A\",\"B\",\"A or B\", sep=\"\\t\")\n",
        "A = True\n",
        "B = True\n",
        "print(A,B,A or B, sep=\"\\t\")\n",
        "A = True\n",
        "B = False\n",
        "print(A,B,A or B, sep=\"\\t\")\n",
        "A = False\n",
        "B = True\n",
        "print(A,B,A or B, sep=\"\\t\")\n",
        "A = False\n",
        "B = False\n",
        "print(A,B,A or B, sep=\"\\t\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "9-Dm4J07z1Ho"
      },
      "source": [
        "print(\"A\",\"B\",\"A and B\", sep=\"\\t\")\n",
        "A = True\n",
        "B = True\n",
        "print(A,B,A and B, sep=\"\\t\")\n",
        "A = True\n",
        "B = False\n",
        "print(A,B,A and B, sep=\"\\t\")\n",
        "A = False\n",
        "B = True\n",
        "print(A,B,A and B, sep=\"\\t\")\n",
        "A = False\n",
        "B = False\n",
        "print(A,B,A and B, sep=\"\\t\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "_hkBN2Ifz4_W"
      },
      "source": [
        "print(\"A\",\"not A\", sep=\"\\t\")\n",
        "A = True\n",
        "print(A, not A, sep=\"\\t\")\n",
        "A = False\n",
        "print(A, not A, sep=\"\\t\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "IDPTItLvw2H1"
      },
      "source": [
        "# Topic 5: Decisions: IfElse"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "yNe4BHCj0TXV"
      },
      "source": [
        "So we know have the idea of yes or no \n",
        "\n",
        "That let's us make decisions"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "W5tcSvvw0afu"
      },
      "source": [
        "##If"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "A_Ut3xB-1Ak7"
      },
      "source": [
        "Do something if condition, or a boolean expression, or a boolean variable is True"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "5xGmuNkO0xG-"
      },
      "source": [
        "print(\"this happens before\")\n",
        "if True:\n",
        "  print(\"this is printed always as condition always True\")\n",
        "print(\"this happens after\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "R2lZcmba04CX"
      },
      "source": [
        "print(\"this happens before\")\n",
        "if False:\n",
        "  print(\"this is never printed\")\n",
        "print(\"this happens after\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "C2RKQYT50dQN"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "if age < 18:\n",
        "  print(\"You are underage!\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "nLXbwKwm09Mq"
      },
      "source": [
        "##IfElse"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "fBtifUeD1TIO"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "cond = age < 18\n",
        "if cond:\n",
        "  print(\"You are underage!\")\n",
        "if not cond:\n",
        "  print(\"You are overage.\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "PJnSHJod1O3f"
      },
      "source": [
        "Natural to want to do something if the boolean was False without reinventing the condition"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "L_Txbdq90_Bu"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "cond = age < 18\n",
        "if cond:\n",
        "  print(\"You are underage!\")\n",
        "else:\n",
        "  print(\"You are overage.\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "MetC5eaS1m5p"
      },
      "source": [
        "print(\"this happens before\")\n",
        "if True:\n",
        "  print(\"this is printed always as condition always True\")\n",
        "else:\n",
        "  print(\"this is never printed\")\n",
        "print(\"this happens after\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "y08mRQ4D1rhG"
      },
      "source": [
        "print(\"this happens before\")\n",
        "if False:\n",
        "  print(\"this is never printed\")\n",
        "else:\n",
        "  print(\"this is printed if condition is false which is always true\")\n",
        "print(\"this happens after\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "-5pcFqhR1zUR"
      },
      "source": [
        "##Elif"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Vr8V0IBu100o"
      },
      "source": [
        "What if we have a bunch of related conditions"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "rS8zoa1015KQ"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "cond1 = age < 17\n",
        "cond2 = age < 18\n",
        "if cond1:\n",
        "  print(\"You are underage!\")\n",
        "if not cond1 and cond2:\n",
        "  print(\"You are underage but almost not!\")\n",
        "if not cond2 and not cond1:\n",
        "  print(\"You aren't underage.\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "2g0W-AwD2fc7"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "cond1 = age < 17\n",
        "cond2 = age < 18\n",
        "if cond1:\n",
        "  print(\"You are underage!\")\n",
        "elif cond2:\n",
        "  print(\"You are underage!\")\n",
        "  print(\"You are underage but almost not!\")\n",
        "else:\n",
        "  print(\"You aren't underage.\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "pB_Rq2ra3BaH"
      },
      "source": [
        "##Nesting"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "QUx1we6w3CR_"
      },
      "source": [
        "Sometimes is clearer to manage your condition logic by nesting it"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "JAUH9LLn3HX_"
      },
      "source": [
        "age = int(input(\"Enter age:\"))\n",
        "cond1 = age < 17\n",
        "cond2 = age < 18\n",
        "if cond2:\n",
        "  print(\"You are underage!\")\n",
        "  if not cond1:\n",
        "    print(\"But you are almost not!\")\n",
        "else:\n",
        "  print(\"You aren't underage.\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "xWE-vTBgHFSp"
      },
      "source": [
        "## Some simple mistakes"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "uYHCxUDKHG8v"
      },
      "source": [
        "#missing :\n",
        "if True\n",
        "  print(\"x\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "HRvPsIUKHLtm"
      },
      "source": [
        "#indentation\n",
        "if False:\n",
        "\tprint(\"x\")\n",
        "   print(\"z\")\n",
        "   "
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "QYJcdwzEHuv6"
      },
      "source": [
        "#Greater than 0 is true\n",
        "if 1:\n",
        "  print(\"hi\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "Tse-HW1UHxJs"
      },
      "source": [
        "#0 is False\n",
        "if 0:\n",
        "  print(\"hi\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "OLw1lYAaHzs9"
      },
      "source": [
        "#Greater than 0 is true\n",
        "if 7:\n",
        "  print(\"hi\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "sLneF0vBH7Nc"
      },
      "source": [
        "#Greater than 0 is true\n",
        "if 0.1:\n",
        "  print(\"hi\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "Lw34u2ZiNLQ9"
      },
      "source": [
        "if -1:\n",
        "  print(\"hi\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "MZpFzQBzNkVq"
      },
      "source": [
        "x = 10 + 1\n",
        "if x > 10:\n",
        "  a = 100\n",
        "print(a)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "fh2Nu6CpNrQj"
      },
      "source": [
        "anotherx = 9\n",
        "if anotherx > 10:\n",
        "  anothera = 100\n",
        "print(anothera)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Jwevfn2UIM5t"
      },
      "source": [
        "## Scope"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "2Himat0MIN0u"
      },
      "source": [
        "A = 1\n",
        "print(dir())\n",
        "del A\n",
        "print(dir())"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "95x3-laLIqnW"
      },
      "source": [
        "\n",
        "A = 1\n",
        "print(dir())\n",
        "del A\n",
        "print(dir())\n",
        "print(A)"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "gKmHKa0iI1r3"
      },
      "source": [
        "A = 1\n",
        "del A\n",
        "age = input(\"Enter an age:\")\n",
        "age = int(age)\n",
        "\n",
        "print(dir())\n",
        "\n",
        "if age > 0:\n",
        "  print(dir())\n",
        "  A = 2\n",
        "  print(dir())\n",
        "\n",
        "print(dir())\n",
        "print(A)\n"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "ewpXp83EJVBp"
      },
      "source": [
        "##Testing"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "ptbiS4mbJW8e"
      },
      "source": [
        "x = int(input(\"Enter an integer:\"))\n",
        "y = int(input(\"Enter an integer:\"))\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "R18whKqtJlLp"
      },
      "source": [
        "print(\"test 1\")\n",
        "#Condition test (conditions are executed)\n",
        "x = 11\n",
        "y = 11\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "Nja6WKS0JqlH"
      },
      "source": [
        "print(\"test 1\")\n",
        "#Statement test (all lines execute)\n",
        "x = 11\n",
        "y = 11\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")\n",
        "\n",
        "print(\"test 2\")\n",
        "#Statement test (all lines execute)\n",
        "x = 1\n",
        "y = 1\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "6kuqIY3WLKVT"
      },
      "source": [
        "print(\"test 1\")\n",
        "#Path test (all orders of lines execute)\n",
        "x = 11\n",
        "y = 11\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")\n",
        "\n",
        "print(\"test 2\")\n",
        "#Path test (all orders of lines execute)\n",
        "x = 1\n",
        "y = 1\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")\n",
        "\n",
        "print(\"test 3\")\n",
        "#Path test (all orders of lines execute)\n",
        "x = 1\n",
        "y = 11\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")\n",
        "\n",
        "print(\"test 4\")\n",
        "#Path test (all orders of lines execute)\n",
        "x = 11\n",
        "y = 1\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "if y > 10:\n",
        "  print(\"y > 10\")\n",
        "else:\n",
        "  print(\"y <= 10\")"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "XliHoOzWm024"
      },
      "source": [
        "x = int(input())\n",
        "if x < 10:\n",
        "  print(x)\n"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "fyuBEUyiLizh"
      },
      "source": [
        "#Boundary testing\n",
        "x = 9\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "  \n",
        "#Boundary testing\n",
        "x = 10\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")\n",
        "\n",
        "#Boundary testing\n",
        "x = 11\n",
        "\n",
        "if x > 10:\n",
        "  print(\"x > 10\")\n",
        "else:\n",
        "  print(\"x <= 10\")"
      ],
      "execution_count": null,
      "outputs": []
    }
  ]
}