{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Теоретический матераил для лабораторных работ\n", "\n", "## \"Инструменты и библиотеки языка Python\"\n", "\n", "# Множества 👩‍💻\n", "\n", "## Создание множеств 📝\n", "\n", "* инициализация путём перечисления элементов множества через запятую в **{}**" ] }, { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0.6, False, None, 'cat', -2000.0, 50, (3, 4, 5), range(0, 3), '!'}\n", "\n" ] } ], "source": [ "a = {50, -2e3, 0.6, None, False, '!', 'cat', (3, 4, 5), range(3)}\n", "print(a)\n", "print(type(a))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* функция **set()** создаёт множества из списков, строк, кортежей и диапазона (класс **range()**)" ] }, { "cell_type": "code", "execution_count": 3, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 3, 7, 9, -7, -1}\n", "\n" ] } ], "source": [ "b = [3, -7, 1, 7, 9, 0, -1]\n", "a = set(b)\n", "print(a)\n", "print(type(a))" ] }, { "cell_type": "code", "execution_count": 5, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{'а', 'с', 'е', 'т', 'д', 'р', 'о', 'и'}\n", "\n" ] } ], "source": [ "b = 'астероид'\n", "a = set(b)\n", "print(a)\n", "print(type(a))" ] }, { "cell_type": "code", "execution_count": 6, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 2, 4, 6, 8, 10, -10, -8, -6, -4, -2}\n", "\n" ] } ], "source": [ "b = range(-10, 11, 2)\n", "a = set(b)\n", "print(a)\n", "print(type(a))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "
\n", " \n", "❗ Пустое множество ❗\n", "\n", "Создать пустое множество можно ТОЛЬКО при помощи функции **set()**! \n", "
\n", "\n", "* генератор множест создаёт множества с помощью **{}**" ] }, { "cell_type": "code", "execution_count": 8, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{1, 4, 9, 16, 25}\n", "\n" ] } ], "source": [ "a = {i ** 2 for i in range(1, 6)}\n", "print(a)\n", "print(type(a))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "
\n", " \n", "❗ Элементы множества — уникальны ❗\n", "\n", "Во множестве не может быть повторов значений элементов! \n", "
" ] }, { "cell_type": "code", "execution_count": 9, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Ожидаем: {1, 6, 1, 2, 1, 1, 4, 3, 1, 5}\n", "Получаем: {1, 2, 3, 4, 5, 6}\n" ] } ], "source": [ "a = {1, 6, 1, 2, 1, 1, 4, 3, 1, 5}\n", "print('Ожидаем: {1, 6, 1, 2, 1, 1, 4, 3, 1, 5}')\n", "print('Получаем:', a)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Работа с множествами 👩‍🏫\n", "\n", "* доступ к элементам множества" ] }, { "cell_type": "code", "execution_count": 14, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{'m', 'd', 's', 'f', 'u', 'e', '.', 'c', 'r'}\n", "m d s f u e . c r " ] } ], "source": [ "a = set('mmcs.sfedu.ru')\n", "print(a)\n", "\n", "for elem in a:\n", " print(elem, end=' ')" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* функция **len()**" ] }, { "cell_type": "code", "execution_count": 15, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "7\n" ] } ], "source": [ "a = {1, 2, 9, -4, 3, 0, 4}\n", "print(len(a))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* операторы **in** и **not in**" ] }, { "cell_type": "code", "execution_count": 16, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{'напрасно', 'гроза.', 'шла', 'дули', 'ветры,', 'Не'}\n", "False\n", "True\n" ] } ], "source": [ "s = '''\n", "Не напрасно дули ветры,\n", "Не напрасно шла гроза.\n", "'''\n", "\n", "a = set(s.split())\n", "print(a)\n", "\n", "print('гроза' in a)\n", "print('гроза' not in a)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* функции **sum()**, **min()** и **max()**" ] }, { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 2, 5, 8, -7}\n", "9\n", "-7\n", "8\n" ] } ], "source": [ "a = {5, -7, 0, 2, 8, 1}\n", "print(a)\n", "print(sum(a))\n", "print(min(a))\n", "print(max(a))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* добавление элементов в множество **add()**" ] }, { "cell_type": "code", "execution_count": 21, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 2, 6, 8, -5, -3}\n", "Сколько элементов хотите добавить в множество? 5\n", "Введите число >>> -9\n", "Введите число >>> 4\n", "Введите число >>> 3\n", "Введите число >>> 4\n", "Введите число >>> 0\n", "{0, 1, 2, 3, 4, 6, 8, -9, -5, -3}\n" ] } ], "source": [ "a = {6, -3, 2, 1, 8, 0, -5}\n", "print(a)\n", "\n", "n = int(input('Сколько элементов хотите добавить в множество? '))\n", "\n", "for _ in range(n):\n", " a.add(int(input('Введите число >>> ')))\n", "print(a)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* удаление отдельных элементов по значению\n", "\n", " * метод **discard()**\n", " \n", " * метод **remove()** (вызывает исключение KeyError, если элемент отсутствует или множество пустое)" ] }, { "cell_type": "code", "execution_count": 22, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n", "{1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n" ] } ], "source": [ "a = set(range(-5, 6))\n", "print(a)\n", "\n", "a.discard(0)\n", "print(a)" ] }, { "cell_type": "code", "execution_count": 40, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n", "{1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n" ] } ], "source": [ "a = set(range(-5, 6))\n", "print(a)\n", "\n", "a.remove(0)\n", "print(a)" ] }, { "cell_type": "code", "execution_count": 24, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "set()\n", "set()\n" ] }, { "ename": "KeyError", "evalue": "0", "output_type": "error", "traceback": [ "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m", "\u001b[1;31mKeyError\u001b[0m Traceback (most recent call last)", "\u001b[1;32m\u001b[0m in \u001b[0;36m\u001b[1;34m\u001b[0m\n\u001b[0;32m 5\u001b[0m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0ma\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m 6\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 7\u001b[1;33m \u001b[0ma\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mremove\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m 8\u001b[0m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0ma\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n", "\u001b[1;31mKeyError\u001b[0m: 0" ] } ], "source": [ "a = set()\n", "print(a)\n", "\n", "a.discard(0)\n", "print(a)\n", "\n", "a.remove(0)\n", "print(a)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* удаление одного произвольного элемента множества методом pop (вызывается исключение KeyError, если удалять значение из пустого множества)" ] }, { "cell_type": "code", "execution_count": 25, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{0, 1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n", "{1, 2, 3, 4, 5, -1, -5, -4, -3, -2}\n" ] } ], "source": [ "a = set(range(-5, 6))\n", "print(a)\n", "\n", "a.pop()\n", "print(a)" ] }, { "cell_type": "code", "execution_count": 26, "metadata": {}, "outputs": [ { "ename": "KeyError", "evalue": "'pop from an empty set'", "output_type": "error", "traceback": [ "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m", "\u001b[1;31mKeyError\u001b[0m Traceback (most recent call last)", "\u001b[1;32m\u001b[0m in \u001b[0;36m\u001b[1;34m\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mset\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mpop\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m", "\u001b[1;31mKeyError\u001b[0m: 'pop from an empty set'" ] } ], "source": [ "print(set().pop())" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* удаление всех элементов множества" ] }, { "cell_type": "code", "execution_count": 27, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{'л', 'к', 'е', 'с', 'т', 'о', 'п', 'у', 'и', 'н', '-'}\n", "set()\n" ] } ], "source": [ "a = set('енотик-полоскун')\n", "print(a)\n", "\n", "a.clear()\n", "print(a)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Операции с множествами 🦉\n", "\n", "С множествами в питоне можно выполнять обычные для математики операции над множествами.\n", "\n", "* **A | B** или **A.union(B)** возвращает множество, являющееся объединением множеств $A$ и $B$. \n", "\n", "* **A & B** или **A.intersection(B)** возвращает множество, являющееся пересечением множеств $A$ и $B$." ] }, { "cell_type": "code", "execution_count": 28, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2000}\n", "{8, 5, 6, 7}\n" ] } ], "source": [ "A = {1, 2, 3, 4, 5, 6, 7, 8}\n", "B = {5, 6, 7, 8, 9, 10, 2000}\n", "\n", "print(A.union(B))\n", "print(A & B)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* **A |= B** или **A.update(B)** добавляет в множество $A$ все элементы из множества $B$.\n", "\n", "* **A &= B** или **A.intersection_update(B)** оставляет в множестве $A$ только те элементы, которые есть в множестве $B$." ] }, { "cell_type": "code", "execution_count": 31, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2000}\n", "{5, 6, 7, 8, 9, 10, 2000}\n" ] } ], "source": [ "A = {1, 2, 3, 4, 5, 6, 7, 8}\n", "B = {5, 6, 7, 8, 9, 10, 2000}\n", "\n", "A.update(B)\n", "print(A)\n", "\n", "A.intersection_update(B)\n", "print(A)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* **A - B** или **A.difference(B)** возвращает разность множеств $A$ и $B$ (элементы, входящие в $A$, но не входящие в $B$).\n", "\n", "* **A -= B** или **A.difference_update(B)** удаляет из множества $A$ все элементы, входящие в $B$." ] }, { "cell_type": "code", "execution_count": 32, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{1, 2, 3, 4}\n", "{1, 2, 3, 4}\n" ] } ], "source": [ "A = {1, 2, 3, 4, 5, 6, 7, 8}\n", "B = {5, 6, 7, 8, 9, 10, 2000}\n", "\n", "print(A.difference(B))\n", "\n", "A.difference_update(B)\n", "print(A)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* **A ^ B** или **A.symmetric_difference(B)** возвращает симметрическую разность множеств $A$ и $B$ (элементы, входящие в $A$ или в $B$, но не в оба из них одновременно).\n", "\n", "* **A ^= B** или **A.symmetric_difference_update(B)** записывает в $A$ симметрическую разность множеств $A$ и $B$." ] }, { "cell_type": "code", "execution_count": 33, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "{1, 2, 3, 4, 9, 10, 2000}\n", "{1, 2, 3, 4, 9, 10, 2000}\n" ] } ], "source": [ "A = {1, 2, 3, 4, 5, 6, 7, 8}\n", "B = {5, 6, 7, 8, 9, 10, 2000}\n", "\n", "print(A.symmetric_difference(B))\n", "\n", "A.symmetric_difference_update(B)\n", "print(A)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "* **A <= B** или **A.issubset(B)** возвращает True, если $A$ является подмножеством $B$. \n", "\n", "* **A >= B** или **A.issuperset(B)** возвращает True, если $B$ является подмножеством $A$.\n", "\n", "* **A == B** возвращает True, если все элементы $A$ принадлежат $B$, все элементы $B$ принадлежат $A$.\n", "\n", "* **A != B** возвращает True, если хотя бы один элемент $A$ не принадлежит $B$ или хотя бы один элемент $B$ не принадлежит $A$.\n", "\n", "* **A < B** эквивалентно A <= B and A != B.\n", "\n", "* **A > B** эквивалентно A >= B and A != B." ] }, { "cell_type": "code", "execution_count": 35, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "False\n", "True\n", "False\n", "True\n", "False\n", "True\n", "True\n" ] } ], "source": [ "A = {1, 2, 3, 4, 5, 6, 7, 8}\n", "B = {5, 6, 7, 8}\n", "\n", "print(A.issubset(B))\n", "print(A.issuperset(B))\n", "print(A == B)\n", "print(B == {8, 5, 6, 7})\n", "print(A < B)\n", "print(A > B)\n", "print(A != B)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], 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