Practical Python Projects

329 Pages·2021·43.194 MB·English

by  Muhammad Yasoob Ullah Khalid

Practical
Python
Projects
Bite-sized weekend projects
to enhance your Python
knowledge
Yasoob Khalid

Practical Python Projects
First Edition, 2021-02-27-rc
by Muhammad Yasoob Ullah Khalid
Copyright © 2021 Muhammad Yasoob Ullah Khalid.
All rights reserved. This book may not be reproduced in any form, in whole or in
part, without written permission from the authors, except in the case of brief
quotations embodied in articles or reviews.
Limit of Liability and Disclaimer of Warranty: The author has used his best
efforts in preparing this book, and the information provided herein “as is”. The
information provided is sold without warranty, either express or implied. Neither
the authors nor Cartwheel Web will be held liable for any damages to be caused
either directly or indirectly by the contents of this book.
Trademarks: Rather than indicating every occurrence of a trademarked name as
such, this book uses the names only in an editorial fashion and to the benefit of
the trademark owner with no intention of infringement of the trademark.
The only authorized vendor or distributor for Practical Python Projects is
Muhammad Yasoob Ullah Khalid. Support this book by only purchasing or
getting it from https://practicalpython.yasoob.me.
First Publishing, August 2020, Version 2020-08-20-alpha
For more information, visit https://yasoob.me.

This book is dedicated to my late grandfather. May his soul rest in peace.

Contents
1 Introduction 1
1.1 Who should read this book . . . . . . . . . . . . . . . . . . . . . . 2
1.2 How to read the book . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Code files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Scraping Steam Using lxml 7
2.1 Exploring Steam . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Start writing a Python script . . . . . . . . . . . . . . . . . . . . . 10
2.3 Fire up the Python Interpreter . . . . . . . . . . . . . . . . . . . . 11
2.4 Extract the titles & prices . . . . . . . . . . . . . . . . . . . . . . 13
2.5 Extracting tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6 Extracting the platforms . . . . . . . . . . . . . . . . . . . . . . . 17
2.7 Putting everything together . . . . . . . . . . . . . . . . . . . . . 19
2.8 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.9 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3 Automatic Invoice Generation 23
3.1 Setting up the project . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2 Creating an invoice template . . . . . . . . . . . . . . . . . . . . . 25
3.3 Generating PDF from HTML . . . . . . . . . . . . . . . . . . . . . 31
3.4 Creating Flask application . . . . . . . . . . . . . . . . . . . . . . 32
3.5 Making invoice dynamic . . . . . . . . . . . . . . . . . . . . . . . 34
3.6 Dynamic invoice to PDF . . . . . . . . . . . . . . . . . . . . . . . . 44
3.7 Getting values from client . . . . . . . . . . . . . . . . . . . . . . 47
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3.8 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.9 Next steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4 FIFA World Cup Twilio Bot 57
4.1 Getting your tools ready . . . . . . . . . . . . . . . . . . . . . . . 57
4.2 Defining the project requirements . . . . . . . . . . . . . . . . . . 59
4.3 Finding and exploring the FIFA API . . . . . . . . . . . . . . . . . 61
4.4 Start writing app.py . . . . . . . . . . . . . . . . . . . . . . . . . . 64
4.5 Getting started with Twilio . . . . . . . . . . . . . . . . . . . . . . 67
4.6 Finishing up app.py . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.7 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
4.8 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
5 Article Summarization & Automated Image Generation 77
5.1 Getting ready . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2 Downloading and Parsing . . . . . . . . . . . . . . . . . . . . . . 80
5.3 Generate the summary . . . . . . . . . . . . . . . . . . . . . . . . 81
5.4 Downloading & Cropping images . . . . . . . . . . . . . . . . . . 85
5.5 Overlaying Text on Images . . . . . . . . . . . . . . . . . . . . . . 89
5.6 Posting the Story on Instagram . . . . . . . . . . . . . . . . . . . 93
5.7 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.8 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6 Making a Reddit + Facebook Messenger Bot 97
6.1 Creating a Reddit app . . . . . . . . . . . . . . . . . . . . . . . . . 98
6.2 Creating an App on Heroku . . . . . . . . . . . . . . . . . . . . . . 99
6.3 Creating a basic Python application . . . . . . . . . . . . . . . . . 100
6.4 Creating a Facebook App . . . . . . . . . . . . . . . . . . . . . . . 105
6.5 Getting data from Reddit . . . . . . . . . . . . . . . . . . . . . . . 110
6.6 Putting everything together . . . . . . . . . . . . . . . . . . . . . 111
6.7 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
6.8 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
7 Cinema Pre-show Generator 127
7.1 Setting up the project . . . . . . . . . . . . . . . . . . . . . . . . . 128
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7.2 Sourcing video resources . . . . . . . . . . . . . . . . . . . . . . . 129
7.3 Getting movie information . . . . . . . . . . . . . . . . . . . . . . 130
7.4 Downloading the trailers . . . . . . . . . . . . . . . . . . . . . . . 134
7.5 Merging trailers together . . . . . . . . . . . . . . . . . . . . . . . 137
7.6 Final Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7.7 Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.8 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
8 Full Page Scroll Animation Video 149
8.1 Installing required libraries . . . . . . . . . . . . . . . . . . . . . . 149
8.2 Getting the Screenshot . . . . . . . . . . . . . . . . . . . . . . . . 151
8.3 Animating the screenshot . . . . . . . . . . . . . . . . . . . . . . 156
8.4 Compositing the clips . . . . . . . . . . . . . . . . . . . . . . . . . 159
8.5 Taking user input . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
8.6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
8.7 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
9 Visualizing Server Locations 167
9.1 Sourcing the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
9.2 Cleaning Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
9.3 Visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
9.4 Basic map plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
9.5 Animating the map . . . . . . . . . . . . . . . . . . . . . . . . . . 182
9.6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
9.7 Next steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
10 Understanding and Decoding a JPEG Image using Python 189
10.1 Getting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
10.2 Different parts of a JPEG . . . . . . . . . . . . . . . . . . . . . . . 190
10.3 Encoding a JPEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
10.4 JPEG decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
10.5 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
11 Making a TUI Email Client 229
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
iii
11.2 IMAP vs POP3 vs SMTP . . . . . . . . . . . . . . . . . . . . . . . . 231
11.3 Sending Emails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
11.4 Receiving Emails . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
11.5 Creating a TUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
11.6 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
12 A Music/Video GUI Downloader 265
12.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
12.2 GUI Mockup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
12.3 Basic Qt app . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
12.4 Layout Management . . . . . . . . . . . . . . . . . . . . . . . . . . 271
12.5 Coding the layout of Downloader . . . . . . . . . . . . . . . . . . 274
12.6 Adding Business Logic . . . . . . . . . . . . . . . . . . . . . . . . 281
12.7 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
12.8 Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
12.9 Next steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
13 Deploying Flask to Production 297
13.1 Basic Flask App . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
13.2 Container vs Virtual Environment . . . . . . . . . . . . . . . . . . 298
13.3 UWSGI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
13.4 NGINX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
13.5 Startup Script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
13.6 Docker File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
13.7 Persistence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
13.8 Docker Compose . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
13.9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
13.10Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
14 Acknowledgements 311
14.1 Bug Submissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
15 Afterword 313
List of Figures 314
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