week0_Python文法_問題解答_ipynb_のコピー.ipynb

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    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
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    "language_info": {
      "name": "python"
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  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "view-in-github",
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      "source": [
        "<a href=\"https://colab.research.google.com/github/1F10230292/2017hello-message/blob/main/week0_Python%E6%96%87%E6%B3%95_%E5%95%8F%E9%A1%8C%E8%A7%A3%E7%AD%94_ipynb_%E3%81%AE%E3%82%B3%E3%83%94%E3%83%BC.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
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      "metadata": {
        "id": "HFUIsTqQZTHV"
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      "outputs": []
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    {
      "cell_type": "markdown",
      "metadata": {
        "id": "MYYAo4yaulnK"
      },
      "source": [
        "## Python文法練習問題 解答集  \n",
        "関連解説動画：https://youtu.be/Z--qkNuCDUU"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "XvMf9d8_umxr"
      },
      "source": [
        "## 練習問題"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "gIrhBfUbu5tj"
      },
      "source": [
        "(1) 変数`x`に整数が格納されているとします。`x`が偶数ならば0、奇数ならば1を返すプログラムを作成してください。"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "2LdgahK0tPtm"
      },
      "source": [
        "# 入力例\n",
        "x = 1"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "colab": {
          "base_uri": "https://localhost:8080/"
        },
        "id": "uMy0IkGdtyVl",
        "outputId": "6d3046de-9394-44d8-f787-c5b3490be1e2"
      },
      "source": [
        "print(x%2) # 2で割った余り"
      ],
      "execution_count": null,
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "1\n"
          ]
        }
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "(2)身長height、体重weightからBMIを計算するプログラムを作成してください。"
      ],
      "metadata": {
        "id": "rrbHd4RY9jGL"
      }
    },
    {
      "cell_type": "code",
      "source": [
        "# 入力例\n",
        "weight = 50 # kg\n",
        "height = 165 # cm\n",
        "\n",
        "bmi = weight /height**2\n",
        "print(bmi)"
      ],
      "metadata": {
        "id": "UE1alFbG948l"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "source": [
        "weight = 50 # kg\n",
        "height = 165 # cm\n",
        "bmi = weight / ((height / 100) ** 2) # 体重/ 身長の2乗\n",
        "print(bmi)"
      ],
      "metadata": {
        "id": "pSankYhy9-c_",
        "outputId": "2685c1ca-a439-46a9-d121-b3bdb65ff801",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "execution_count": null,
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "18.36547291092746\n"
          ]
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "dcTKOEWCu9iJ"
      },
      "source": [
        "(3) 要素がすべて整数値であって、長さが1以上のリストが変数xに格納されているとします。xの要素の中で最も大きい要素を返すプログラムを作成してください。ただし、max関数などは使用せず、ループ（for文での繰り返し）で実現してください。"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "XRxhnIrOvCy6"
      },
      "source": [
        "# 入力例\n",
        "x = [1, 5, 4, 3]"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "colab": {
          "base_uri": "https://localhost:8080/"
        },
        "id": "OzclAG0PvW8T",
        "outputId": "b51ba397-0134-4f4e-89f1-4ee25679b9b2"
      },
      "source": [
        "# 最大値を変数maxに格納する\n",
        "max = x[0] # maxの初期値は配列の先頭にする\n",
        "for i in x:\n",
        "    if max < i:\n",
        "        max = i # maxをiに入れ替える\n",
        "print(max)"
      ],
      "execution_count": null,
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "5\n"
          ]
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "5x-F_MuUrA71"
      },
      "source": [
        "(4) 長さが1以上の文字列を引数`x`とし、`x`の最後の1文字を返す関数`f`を定義してください。"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "8MMtKI6BxBd-"
      },
      "source": [
        "# 入力例\n",
        "x = 'python'"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 36
        },
        "id": "y1sMF1gOyKDG",
        "outputId": "2ec58e83-2899-4612-94a3-2e520b364ace"
      },
      "source": [
        "def f(x):\n",
        "    length = len(x) # 文字列の長さ\n",
        "    return x[length - 1] # 0から始まるので、lengthより１つ小さいインデックスを指定\n",
        "f(x)"
      ],
      "execution_count": null,
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "'x'"
            ],
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              "type": "string"
            }
          },
          "metadata": {},
          "execution_count": 6
        }
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "# 別解\n",
        "def f(x):\n",
        "    return x[-1]\n",
        "f(x)"
      ],
      "metadata": {
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 36
        },
        "id": "1fyyn50mZloT",
        "outputId": "45d1d64b-c9b1-4886-bfe3-98553dbbaeba"
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      "execution_count": null,
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          "output_type": "execute_result",
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            "text/plain": [
              "'x'"
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          "metadata": {},
          "execution_count": 7
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "X3QZvPIorA71"
      },
      "source": [
        "(5) 辞書を引数`x`とし、`x`に格納されているキーの数を返す関数`f`を定義してください。"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "lofLzjq7ywER"
      },
      "source": [
        "# 入力例\n",
        "x = {\"a\": 1, \"b\": 2, \"c\": 3, 'd':4, 'e':5}"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "colab": {
          "base_uri": "https://localhost:8080/"
        },
        "id": "tvJkFZ7czaQ2",
        "outputId": "85f23211-550e-48ed-c7d6-ca11ba207627"
      },
      "source": [
        "def f(x):\n",
        "    num_key = x.keys() # keys()は、辞書のキーを取得する関数\n",
        "    return len(num_key) # num_keyの長さがキーの数となる\n",
        "f(x)"
      ],
      "execution_count": null,
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "5"
            ]
          },
          "metadata": {},
          "execution_count": 13
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "BpIsk38qrA72"
      },
      "source": [
        "(6) リストを引数`x`とし、`x`の要素を逆順に並べたリストを返す関数`f`を定義してください。ただし、`reversed`関数などは使用せず、ループやリストのスライスで実現してください。"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "rBt1DRLy0lVJ"
      },
      "source": [
        "# 入力例\n",
        "x = [3, 9, 7, 1, 0]"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "76Sb5A6U3SUP",
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          "base_uri": "https://localhost:8080/"
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        "outputId": "19af9612-ed77-46a3-8904-fd6577e5d9fc"
      },
      "source": [
        "def f(x):\n",
        "    reverse = [] # 結果を入れる変数(空箱)を用意する\n",
        "    length = len(x) # 繰り返し回数\n",
        "    for i in range(1,length + 1):\n",
        "        reverse.append(x[-i]) # 後ろに追加していく\n",
        "    return reverse\n",
        "\n",
        "f(x)"
      ],
      "execution_count": null,
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "[0, 1, 7, 9, 3]"
            ]
          },
          "metadata": {},
          "execution_count": 15
        }
      ]
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