161 lines
3.2 KiB
Plaintext
161 lines
3.2 KiB
Plaintext
{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {
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"pycharm": {
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"name": "#%% md\n"
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},
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"slideshow": {
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"slide_type": "slide"
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}
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},
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"source": [
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"# Software Entwicklung \n",
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"\n",
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"## Kapitel 9: IO\n",
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"\n",
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"### 9.4 Dateien schreiben\n",
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"\n",
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"Voraussetzung dafür, dass in eine Datei geschrieben werden kann,\n",
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"ist ein passender Bearbeitungsmodus."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"pycharm": {
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"name": "#%%\n"
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}
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},
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"outputs": [],
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"source": [
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"with open(\"093a Textdatei\", \"w\") as f:\n",
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" f.write(\"Nürnberg ist schön!\")\n",
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"\n",
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"with open(\"093a Textdatei\", \"r\") as f:\n",
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" print(f.read())"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {
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"slideshow": {
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"slide_type": "slide"
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}
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},
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"source": [
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"Wird der Schreib-/Lesekopf zurückgesetzt, kann der bestehende Inhalt überschrieben werden."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"pycharm": {
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"name": "#%%\n"
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}
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},
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"outputs": [],
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"source": [
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"with open(\"093a Textdatei\", \"w\") as f:\n",
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" f.write(\"Nürnberg ist nice!\")\n",
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" pos = f.tell()-5\n",
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" f.seek(pos)\n",
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" f.write(\"schön!\")\n",
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"\n",
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"with open(\"093a Textdatei\", \"r\") as f:\n",
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" print(f.read())"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {
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"pycharm": {
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"name": "#%% md\n"
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},
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"slideshow": {
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"slide_type": "slide"
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}
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},
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"source": [
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"Durch den Bearbeitungsmodus <code>'r+'</code> ist es auch\n",
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"möglich, mit einem Datei-Objekt zu lesen und zu schreiben."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"pycharm": {
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"name": "#%%\n"
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}
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},
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"outputs": [],
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"source": [
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"with open(\"093a Textdatei\", \"r+\") as f:\n",
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" f.write(\"Nürnberg ist nice!\")\n",
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" pos = f.tell()-5\n",
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" f.seek(pos)\n",
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" f.write(\"schön!\")\n",
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" f.seek(0)\n",
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" print(f.read())"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {
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"slideshow": {
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"slide_type": "slide"
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}
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},
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"source": [
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"Anders als bei <code>print</code> wird bei <code>write</code>\n",
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"kein Zeilenwechsel angehängt; es muss also ggf. selbst\n",
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"hinzugefügt werden."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"pycharm": {
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"name": "#%%\n"
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}
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},
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"outputs": [],
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"source": [
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"with open(\"093a Textdatei\", \"r+\") as f:\n",
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" f.write(\"Zeile 1\")\n",
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" f.write(\"Zeile 2\\n\")\n",
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" f.write(\"Zeile 3\\n\")\n",
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" f.seek(0)\n",
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" print(f.readline())"
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]
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}
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],
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"metadata": {
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"celltoolbar": "Slideshow",
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"kernelspec": {
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"display_name": "Python 3 (ipykernel)",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.9.9"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 1
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}
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