python-kurs-softed/notebooks/controlflow.ipynb

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{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Kontrollstrukturen und Vergleichsoperatoren"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Verzweigung (Branching)"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Hmm, ob das so stimmt?\n"
]
}
],
"source": [
"# if / else / elif\n",
"\n",
"alter = -1\n",
"\n",
"if alter >= 16:\n",
" print(\"Nicht vergessen: am 9.6.2024 ist Europa-Wahl!\")\n",
"elif alter > 0:\n",
" print(\"Schön, dass du geboren bist!\")\n",
"else:\n",
" print(\"Hmm, ob das so stimmt?\")"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Nach Süden, nach Süden!\n"
]
}
],
"source": [
"richtung = \"s\"\n",
"\n",
"if richtung == \"n\":\n",
" print(\"Auf in den hohen Norden!\")\n",
"elif richtung == \"s\":\n",
" print(\"Nach Süden, nach Süden!\")\n",
"elif richtung == \"w\":\n",
" print(\"Go west!\")\n",
"elif richtung == \"o\":\n",
" print(\"Bin schon da.\")\n"
]
},
{
"cell_type": "code",
"execution_count": 15,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Auf in den hohen Norden!\n"
]
}
],
"source": [
"# match\n",
"\n",
"# richtung = input(\"Wo soll's denn lang gehen? \")\n",
"richtung = \"n\"\n",
"\n",
"match richtung:\n",
" case \"n\" | \"norden\":\n",
" print(\"Auf in den hohen Norden!\")\n",
" case \"s\" | \"süden\":\n",
" print(\"Nach Süden, nach Süden!\")\n",
" case \"w\" | \"westen\":\n",
" print(\"Go west!\")\n",
" case \"o\" | \"osten\":\n",
" print(\"Bin schon da.\")\n",
" case _:\n",
" print(\"Das Glück liegt manchmal abseits des direkten Wegs!\")"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Schleifen"
]
},
{
"cell_type": "code",
"execution_count": 16,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Schleifendurchlauf Nr. 0\n",
"Schleifendurchlauf Nr. 1\n",
"Schleifendurchlauf Nr. 2\n",
"Schleifendurchlauf Nr. 3\n",
"Schleifendurchlauf Nr. 4\n"
]
}
],
"source": [
"# for\n",
"\n",
"for i in range(5):\n",
" print(\"Schleifendurchlauf Nr. \", i)\n"
]
},
{
"cell_type": "code",
"execution_count": 17,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Summer der Zahlen 1-10: 55\n"
]
}
],
"source": [
"result = 0\n",
"for i in range(1, 11):\n",
" result += i\n",
"print(\"Summe der Zahlen 1-10:\", result)"
]
},
{
"cell_type": "code",
"execution_count": 18,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"9 passt in die Reihe\n"
]
}
],
"source": [
"for i in (2, 4, 6, 8, 9, 10):\n",
" if i % 2:\n",
" print(i, \"passt nicht in die Reihe\")"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"10 ... 9 ... 8 ... 7 ... 6 ... 5 ... 4 ... 3 ... 2 ... 1 ... Lift off!\n"
]
}
],
"source": [
"# while\n",
"\n",
"i = 10\n",
"while i > 0: # or: while True:\n",
" print(i, \"... \", end=\"\")\n",
" i -= 1\n",
"print(\"Lift off!\")"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"10\n",
"11\n",
"12\n",
"14\n",
"15\n",
"16\n",
"17\n",
"18\n",
"19\n"
]
}
],
"source": [
"# continue\n",
"\n",
"for i in range(10, 20):\n",
" if i == 13:\n",
" continue\n",
" print(i)"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Iteration: 142\n"
]
}
],
"source": [
"# break\n",
"\n",
"i = 0\n",
"result = 0\n",
"maximum = 10_000\n",
"\n",
"while True:\n",
" result += i\n",
"\n",
" if result >= maximum:\n",
" print(\"Iteration: \", i+1)\n",
" break\n",
"\n",
" i += 1\n"
]
},
{
"cell_type": "code",
"execution_count": 10,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"q ist Buchstabe Nr. 17 des dt. Alphabets.\n"
]
}
],
"source": [
"alphabet = \"abcdefghifklmnopqrstuvwxyz\"\n",
"buchstabe = \"q\"\n",
"i = 0\n",
"for char in alphabet:\n",
" i += 1\n",
" if char == buchstabe:\n",
" print(buchstabe, \"ist Buchstabe Nr.\", i, \"des dt. Alphabets.\")\n",
" break\n"
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"q ist Buchstabe Nr. 17 des dt. Alphabets.\n"
]
}
],
"source": [
"# einfacher:\n",
"\n",
"for i, char in enumerate(alphabet):\n",
" if char == buchstabe:\n",
" print(buchstabe, \"ist Buchstabe Nr.\", i + 1, \"des dt. Alphabets.\")\n",
" break"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Funktionen"
]
},
{
"cell_type": "code",
"execution_count": 14,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"256 256 100\n"
]
}
],
"source": [
"# Aufruf eingebauter Funktionen\n",
"\n",
"x = pow(2, 8)\n",
"y = max(x, 100)\n",
"z = min(max(0, x), 100)\n",
"print(x, y, z)"
]
},
{
"cell_type": "code",
"execution_count": 15,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
"\n"
]
}
],
"source": [
"# optionale Parameter\n",
"\n",
"print()\n",
"print(\"\")"
]
},
{
"cell_type": "code",
"execution_count": 16,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"5\n"
]
}
],
"source": [
"# eigene Funktionen\n",
"\n",
"def add(a, b):\n",
" return a + b\n",
"\n",
"print(add(2, 3))"
]
},
{
"cell_type": "code",
"execution_count": 20,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"15\n",
"24\n"
]
}
],
"source": [
"# Keyword arguments\n",
"\n",
"print(add(a=5, b=10))\n",
"print(add(4, b=20))"
]
},
{
"cell_type": "code",
"execution_count": 21,
"metadata": {},
"outputs": [
{
"ename": "SyntaxError",
"evalue": "positional argument follows keyword argument (1525390589.py, line 2)",
"output_type": "error",
"traceback": [
"\u001b[0;36m Cell \u001b[0;32mIn[21], line 2\u001b[0;36m\u001b[0m\n\u001b[0;31m print(add(a=6, 10))\u001b[0m\n\u001b[0m ^\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m positional argument follows keyword argument\n"
]
}
],
"source": [
"# Das geht nicht:\n",
"print(add(a=6, 10))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Vergleichsausdrücke"
]
},
{
"cell_type": "code",
"execution_count": 23,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"False\n",
"True\n",
"False\n",
"True\n",
"True\n",
"False\n",
"True\n",
"True\n"
]
}
],
"source": [
"a = 10\n",
"b = 50\n",
"c = 2\n",
"d = 5 * a\n",
"\n",
"print(a == b)\n",
"print(a != d)\n",
"print(a > b)\n",
"print(a > c)\n",
"print(a >= c)\n",
"print(c > a)\n",
"print(c < b)\n",
"print(c >= 2)"
]
},
{
"cell_type": "code",
"execution_count": 32,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"True\n",
"True\n",
"False\n"
]
}
],
"source": [
"# Negation\n",
"\n",
"print(not c > a)\n",
"print(not a == b) # klarer: a != b\n",
"print(not b != d) # klarer: b == d\n",
"print(not a > c)"
]
},
{
"cell_type": "code",
"execution_count": 31,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"True\n",
"True\n"
]
}
],
"source": [
"# logische Kombination\n",
"\n",
"print(b > a and a > c)\n",
"print(a > b or a > c)\n",
"print(not a < c and b >= d)"
]
},
{
"cell_type": "code",
"execution_count": 41,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"True\n",
"True\n",
"False\n"
]
}
],
"source": [
"# Bool'scher (True/False) Wert von Integers, Floats und Strings \n",
"print(a > c)\n",
"print(bool(a > c)) ## redundant, da Vergleichsausdrücke immer einen bool'schen Wert haben\n",
"# Aber:\n",
"print(bool(a))\n",
"print(not a) # auch ein bool'scher Ausdruck\n"
]
},
{
"cell_type": "code",
"execution_count": 45,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"False\n",
"True\n",
"True\n",
"False\n",
"True\n",
"True\n",
"True\n",
"True\n",
"False\n",
"True\n"
]
}
],
"source": [
"print(bool(0))\n",
"print(bool(1))\n",
"print(bool(-1))\n",
"print(bool(0.0))\n",
"print(bool(0.1))\n",
"print(bool(-0.1))\n",
"print(bool(\"True\"))\n",
"print(bool(\"False\")) # !!!\n",
"print(bool(\"\"))\n",
"print(bool(\"\\0\"))\n"
]
}
],
"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
}