3_python決策與選擇結構_20201026.ipynb

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      "name": "3_python決策與選擇結構教學版_20201026.ipynb",
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      ]
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    {
      "cell_type": "markdown",
      "metadata": {
        "id": "OaJKqW9Dch0Y"
      },
      "source": [
        "# python決策與選擇結構\n",
        "```\n",
        "[1]if\n",
        "[2]if ...elsif\n",
        "[3]if ...else\n",
        "[4]if ...elsif ...else\n",
        "[5]各種判斷條件\n",
        "   AND\n",
        "   OR\n",
        "```\n",
        "```\n",
        "問題:有何差別\n",
        "[2]if ...elsif\n",
        "[3]if ...else\n",
        "```\n",
        "```\n",
        "單向判斷式（if⋯）: 是非題｜對的才要做\n",
        "雙向判斷式（if⋯else）: 二選一｜一定要選的\n",
        "多向判斷式（if⋯elif⋯else）: 多選一｜一定要選的\n",
        "```\n",
        "```\n",
        "程式流程控制　之 選擇(判斷) SELECTION /DECISION\n",
        "Python 程式碼縮排\n",
        "Python 語言以冒號「:」及縮排來表示程式區塊\n",
        "縮排為 1 個 Tab 鍵或 4 個空白鍵\n",
        "https://www.w3schools.com/python/python_conditions.asp\n",
        "```\n",
        "## Python沒有switch\n",
        "```\n",
        "switch(變數名稱或運算式) {\n",
        "    case 符合數字或字元:\n",
        "        陳述句一;\n",
        "        break;\n",
        "    case 符合數字或字元:\n",
        "        陳述句二;\n",
        "        break;\n",
        "    default:\n",
        "        陳述三;\n",
        "        break;\n",
        "}\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "ATwc25Q2clcb"
      },
      "source": [
        "# [1]if\n",
        "\n",
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 33\n",
        "b = 200\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "bm4GtzT5cnnj"
      },
      "source": [
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 33\n",
        "b = 20\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "```"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "a4Kifh8eeFW3"
      },
      "source": [
        "if 100 == \"100\":\n",
        "    print(\"Hello\")"
      ],
      "execution_count": 6,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "S7C9Vh4xcqN4"
      },
      "source": [
        "# [2]if ...elsif\n",
        "\n",
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 32\n",
        "b = 33\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "elif a == b:\n",
        "  print(\"a and b are equal\")\n",
        "\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "l_euwOcPctBT"
      },
      "source": [
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 33\n",
        "b = 33\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "elif a == b:\n",
        "  print(\"a and b are equal\")\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "YxeiPkFJcvfa"
      },
      "source": [
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 35\n",
        "b = 33\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "elif a == b:\n",
        "  print(\"a and b are equal\")\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "4v-m5ukFcyUp"
      },
      "source": [
        "# 雙向判斷式（if⋯else）: 二選一｜一定要選的\n",
        "\n",
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 200\n",
        "b = 33\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "else:\n",
        "  print(\"b is not greater than a\")\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "7S9Zpdxfc098"
      },
      "source": [
        "# [4]if ...elsif ...else  多選一｜一定要選的\n",
        "\n",
        "底下程式執行後結果為何?\n",
        "```\n",
        "a = 200\n",
        "b = 33\n",
        "\n",
        "if b > a:\n",
        "  print(\"b is greater than a\")\n",
        "elif a == b:\n",
        "  print(\"a and b are equal\")\n",
        "else:\n",
        "  print(\"a is greater than b\")\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Y1IE6lhfdCql"
      },
      "source": [
        "# [5]各種判斷條件   AND  OR\n",
        "\n",
        "底下程式執行後結果為何?\n",
        "```\n",
        "#判斷是否為閏年\n",
        "\n",
        "year= eval(input(\"請輸入年\"))\n",
        "\n",
        "if ((year%400==0) or (year%4==0 and year%100!=0)):\n",
        "  print(\"{0} 是閏年\".format(year))\n",
        "else:\n",
        "  print(\"{0} 不是閏年\".format(year))\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "stbXjqM5dKNZ"
      },
      "source": [
        "# 歲月匆匆程式開發\n",
        "```\n",
        "輸入:年月日\n",
        "輸出:已經過了多少日\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "FdJMoFlmdMwp"
      },
      "source": [
        "底下程式執行後結果為何?\n",
        "```\n",
        "year, month, day = eval(input(\"請輸入年月日\"))\n",
        "year, month, day\n",
        "\n",
        "#請輸入年月日2019,5,22\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "c1MmiNTIdW_-"
      },
      "source": [
        "底下程式執行後結果為何?\n",
        "```\n",
        "year, month, day = eval(input(\"請輸入年月日::\"))\n",
        "```\n",
        "```\n",
        "day_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]\n",
        "\n",
        "if year%400==0 or (year%4==0 and year%100!=0):\t\n",
        "  day_month[1] = 29\n",
        "```\n",
        "```\n",
        "if month==1:\n",
        "    print(day)\n",
        "else:\n",
        "    print(sum(day_month[:month-1])+day)\n",
        "```"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "wfvp-LmZrXLz"
      },
      "source": [
        "\n",
        "# 多向判斷式（if⋯elif⋯else）:收銀台程式開發\n",
        "```\n",
        "百貨公司週年慶活動血拼大打折，\n",
        "吸引很多顧客上門，\n",
        "公司決定再加碼回饋客戶，\n",
        "\n",
        "只要客戶消費\n",
        "金額在 100000 元以上就打八折，\n",
        "金額在 50000 元以上就打八五折，\n",
        "金額在 30000 元以上就打九折，\n",
        "金額在 10000 元以上就打九五折，\n",
        "金額在 10000 元以下就不打折\n",
        "\n",
        "請幫該公司設計這個收銀台的程式，\n",
        "輸入顧客購買金額後，計算顧客應付的金錢。\n",
        "```\n",
        "```\n",
        "money = int(input(\"請輸入購物金額：\"))\n",
        "\n",
        "if(money >= 10000):\n",
        "    if(money >= 100000):\n",
        "        print(money * 0.8, end=\" 元\\n\")  #八折\n",
        "    elif(money >= 50000):\n",
        "        print(money * 0.85, end=\" 元\\n\")  #八五折\n",
        "    elif(money >= 30000):\n",
        "        print(money * 0.9, end=\" 元\\n\")  #九折\n",
        "    else:\n",
        "        print(money * 0.95, end=\" 元\\n\")  #九五折\n",
        "else:\n",
        "    print(money, end=\" 元\\n\")  #未打折\n",
        "```"
      ]
    }
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