{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Erweiterte Datentypen: Container" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Listen und Tupel" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Listenliterale\n", "\n", "values = [5, 10, 20, 30, 50]\n", "print(values)\n", "fractions = [0.5, 0.6, 0.8, 1.0, 1.2]\n", "print(fractions)\n", "names = [\"Joe\", \"Alice\", \"Bob\", \"Charly\"]\n", "print(names)\n", "heap = [1, \"Joe\", 1.4, \"Alice\", 100]\n", "print(heap)\n", "single = [\"one\"]\n", "leer = []\n", "auch_leer = list()\n", "print(single, leer, auch_leer)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Tuplelliterale\n", "values = (5, 10, 20, 30, 50)\n", "print(values)\n", "fractions = (0.5, 0.6, 0.8, 1.0, 1.2)\n", "print(fractions)\n", "names = (\"Joe\", \"Alice\", \"Bob\", \"Charly\")\n", "print(names)\n", "heap = (1, \"Joe\", 1.4, \"Alice\", 100)\n", "print(heap)\n", "t_single = (\"one\",)\n", "t_auch_single = \"one\",\n", "t_leer = ()\n", "t_auch_leer = tuple()\n", "print(t_single, t_auch_single, t_leer, t_auch_leer)\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Umwandlung\n", "\n", "l = [1, 2, 3, 4, 5]\n", "t = tuple(l)\n", "print(l, t)\n", "l = [10, 20, 30, 40, 50]\n", "print(l, t)\n", "l2 = list(t)\n", "print(l2)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "s = \"hallo\"\n", "print(list(s))\n", "print(tuple(s))" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Indizierung" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "seasons = [\"Frühling\", \"Sommer\", \"Herbst\", \"Winter\"]\n", "print(seasons[0]) # Erstes Element hat Index 0!\n", "print(seasons[2])\n", "print(seasons[-1]) # Negative Indices zählen vom letzten Element rückwärts\n", "print(seasons[-3])" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Ungültige Indizes führen zu einem Fehler (IndexError Exception)\n", "print(seasons[4]) # 4 Elemente => gültige Indizes 0..3" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Ebenso\n", "print(seasons[-5])" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Zuweisung an einzelne Listenelemente\n", "\n", "l = [1, 2, 3, 4, 5]\n", "l[1] = -1\n", "print(l)\n", "l[3] = \"vier\"\n", "print(l)\n", "l[-1] = 5.0\n", "print(l)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Indizierung funktioniert auch mit Tupeln mit der selben Syntax\n", "t = (1, 2, 3, 4, 5)\n", "print(t[0], t[-2])" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Aber Tuple sind nicht-veränderbar (immutable)\n", "\n", "t[2] = \"drei\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Slicing" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "l = list(range(10)) # l = [0, 1, ..., 9]\n", "print(l[2:4]) # Start ist inklusiv, Ende nicht!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Auch wenn kein oder nur ein Element \"übrig bleibt\", ist das Ergebnis eine Liste\n", "\n", "print(l[2:3])\n", "print(l[9:-1])" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Start und End können leer, also \"offen\", sein\n", "\n", "print(l[5:])\n", "print(l[:3]) # auch hier ist der Ende-Index nicht-inklusiv!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Sind Start und Ende leer, ist das Ergebnis eine Kopie der Liste / des Tuples\n", "\n", "l = [1, 2, 3]\n", "l2 = l[:]\n", "l[0] = 999\n", "print(l)\n", "print(l2)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Zuweisung an Listenslices ist möglich!\n", "\n", "seasons = [\"Winter\", \"Frühling\", \"Sommer\", \"Herbst\"]\n", "seasons[1:1] = [\"Karneval\"]\n", "print(seasons)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Listen oder Tuples können mit + zu einer/m neuen Liste / Tupel zusamengefügt werden \n", "\n", "items = [1, 2, 3]\n", "more_items = items + [\"one\", \"two\", \"three\"]\n", "print(more_items)\n", "items[1:2] = []\n", "print(items)\n", "print(more_items)\n", "more_items += [4, 6, 6]\n", "print(more_items)\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "t = (1, 2, 3)\n", "t2 = t + (4, 5, 6)\n", "print(t)\n", "print(t2)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Achtung: \n", "\n", "t = (1, 2, 3)\n", "t2 = t\n", "print(t)\n", "print(t2)\n", "print(t is t2)\n", "t += (1, 2, 3) # Tuples sind immutable, t ist eine neue Kopie!\n", "print(t)\n", "print(t2)\n", "print(t is t2)\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Dictionaries" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Auch Hashtables, Lookup Tables usw. genannt\n", "# Tabellen mit Zurdnung von Schlüsseln zu werten (Key-value pairs)\n", "\n", "d = {}\n", "# oder:\n", "d = dict()\n", "print(d)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "scores = {\n", " \"blue team\": 40,\n", " \"green team\": 45,\n", " \"red team\": 30,\n", " \"black team\": 60\n", "}\n", "print(scores)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Look up\n", "\n", "print(\"The red team scored:\", scores[\"red team\"])" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Neue Key/Value Paare hinzufügen (Dictionaries sind veränderbar!)\n", "\n", "scores[\"white team\"] = 45\n", "scores[\"rainbow team\"] = 50\n", "print(scores)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Umwandlung\n", "\n", "print(tuple(scores)) # Tupel der Keys\n", "\n", "print(list(scores)) # Liste der Keys\n", "\n", "print(tuple(scores.keys()))" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Iteration\n", "\n", "for key in scores:\n", " print(\"Das\", key, \"hat\", scores[key], \"Punkte.\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Iteration über Key/Value Paare\n", "\n", "print(scores.items())\n", "\n", "for key, value in scores.items():\n", " print(\"Das\", key, \"hat\", value, \"Punkte.\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Keys müsen keine Strings, aber immutable sein\n", "# => Integers, Floats, Tuples sind ok\n", "\n", "numbers = {1: \"one\", 2: \"two\", 3: \"three\"}\n", "print(numbers[2]) # Achtung: nicht mit Listenindex verwechseln!\n", "\n", "pixels = {\n", " (0, 5): 'r',\n", " (2, 7): 'b', \n", " (3, 10): 'r',\n", " (5, 2): 'g',\n", " (5, 5): 'b', \n", "}\n", "\n", "for row in range(6):\n", " for col in range(10):\n", " if (row, col) in pixels:\n", " print(pixels[(row, col)], end=\"\")\n", " else:\n", " print(\".\", end=\"\")\n", " print()\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Sets (Mengen)\n", "\n", "Mengen sind wie unsortierte Tupel, in denen jedes Element nur einmal vorkommen kann." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "s = set([])\n", "print(s) # leeres Set wird repräsentiert mit 'set()', nicht '{}' (leeres Dictionary!)\n", "\n", "s2 = set([2,3,5])\n", "s2.add(4)\n", "s2.add(5) # Schon im Set enthalten\n", "print(s2)\n", "\n", "for i in s2:\n", " print(i)\n", "\n", "print()\n", "\n", "s2.add(1)\n", "s2.remove(4)\n", "\n", "for i in s2:\n", " print(i) # Reihenfolge nach Änderung nicht garantiert gleich!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Kombination\n", "\n", "s1 = set([1, 2, 3, 5])\n", "s2 = set([4, 5, 6, 7])\n", "\n", "# Union (alle Elemente aus beiden Sets)\n", "print(s1 | s2)\n", "\n", "# Intersection (alle Elemente, die sowohl in s1 als auch s2 sind)\n", "print(s1 & s2)\n", "\n", "# Difference (alle Elemente in s1, die nicht auch in s2 sin)\n", "print(s1 - s2)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Siehe: https://docs.python.org/3/library/stdtypes.html#set-types-set-frozenset" ] } ], "metadata": { "kernelspec": { "display_name": "softed", "language": "python", "name": "softed" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.11.8" } }, "nbformat": 4, "nbformat_minor": 2 }