The ultimate guide to coding with Python Pi 2 projects inside Learn to use Pythont Program games t Get creative with Pi NEW Welcome to The Python Python is an incredibly versatile, expansive language which, due to its similarity to everyday language, is surprisingly easy to learn even for inexperienced programmers. It has seen a huge increase in popularity since the release and rise of the Raspberry Pi, for which Python is the officially recognised programming language. In The Python Book, you’ll find plenty of creative projects to help you get to grips with the combination of your Raspberry Pi and Python’s powerful functionality, but there are also plenty of tutorials that focus on Python’s effectiveness away from the Raspberry Pi. You’ll learn all about how to code with Python from the very beginning with our comprehensive masterclass, then go on to complete tutorials to consolidate your skills and become fluent in the language while also improving your computing experience. You’ll learn how to make Python work for you with tutorials on coding with Django, Flask, Pygame and even more useful third-party applications and frameworks. Get ready to become a true Python expert with the wealth of information contained within these pages. The Python Imagine Publishing Ltd Richmond House 33 Richmond Hill Bournemouth Dorset BH2 6EZ +44 (0) 1202 586200 Website: www.imagine-publishing.co.uk Twitter: @Books_Imagine Facebook: www.facebook.com/ImagineBookazines Publishing Director Aaron Asadi Head of Design Ross Andrews Production Editor Alex Hoskins Senior Art Editor Greg Whitaker Designer Perry Wardell-Wicks Printed by William Gibbons, 26 Planetary Road, Willenhall, West Midlands, WV13 3XT Distributed in the UK, Eire & the Rest of the World by Marketforce, Blue Fin Building, 110 Southwark Street, London, SE1 0SU Tel 0203 148 3300 www.marketforce.co.uk Distributed in Australia by Network Services (a division of Bauer Media Group), Level 21 Civic Tower, 66-68 Goulburn Street, Sydney, New South Wales 2000, Australia Tel +61 2 8667 5288 Disclaimer The publisher cannot accept responsibility for any unsolicited material lost or damaged in the post. All text and layout is the copyright of Imagine Publishing Ltd. Nothing in this bookazine may be reproduced in whole or part without the written permission of the publisher. All copyrights are recognised and used specifically for the purpose of criticism and review. Although the bookazine has endeavoured to ensure all information is correct at time of print, prices and availability may change. This bookazine is fully independent and not affiliated in any way with the companies mentioned herein. The Python Book © 2015 Imagine Publishing Ltd ISBN 9781785460609 Part of the bookazine series 5IF Python $POUFOUT 8( FUTUBSUFE 8PSLXJUI1ZUIPO $SFBUFXJUI1ZUIPO XJUI1ZUIPO .BTUFSUIFCBTJDTUIFSJHIUXBZ 74$ SFBUFEZOBNJDUFNQMBUFT 108# VJMEUJDUBDUPFXJUI,JWZ 6TF+JOKB 'MBTLBOENPSF 1SPHSBNOPVHIUTBOEDSPTTFT 16 FTTFOUJBM 78. 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i1ZUIPOJTFYQBOTJWF CVUZPVMMCF 148& OIBODFZPVSCMPH $PNQMFUFZPVSCMPHXJUIBEEPOT BOFYQFSUCFGPSFZPVLOPXJUw 5IF1ZUIPO#PPL7 Get started with Python Get started with Python Always wanted to have a go at programming? No more excuses, because Python is the perfect way to get started! ython is a great programming language for libraries to create a windowed application, or you could both beginners and experts. It is designed with try something a little more ambitious like an app such Pcode readability in mind, making it an excellent as creating one using Python’s Bluetooth and Input choice for beginners who are still getting used to libraries to capture the input from a USB keyboard and various programming concepts. relay the input events to an Android phone. The language is popular and has plenty of libraries For this tutorial we’re going to be using Python 2.x available, allowing programmers to get a lot done with since that is the version that is most likely to be installed relatively little code. on your Linux distribution. You can make all kinds of applications in Python: In the following tutorials, you’ll learn how to create you could use the Pygame framework to write popular games using Python programming. We’ll also simple 2D games, you could use the GTK show you how to add sound and AI to these games. 8 The Python Book Get started with Python The Python Book 9 Get started with Python Hello World Variables and data types Let’s get stuck in, and what better way than with the A variable is a name in source code that is associated with an programmer’s best friend, the ‘Hello World’ application! Start area in memory that you can use to store data, which is then by opening a terminal. Its current working directory will be your called upon throughout the code. The data can be one of many home directory. It’s probably a good idea to make a directory for types, including: the fi les we’ll be creating in this tutorial, rather than having them loose in your home directory. You can create a directory called Python using the command mkdir Python. You’ll then want to Integer Stores whole numbers change into that directory using the command cd Python. The next step is to create an empty fi le using the command Float Stores decimal numbers ‘touch’ followed by the fi lename. Our expert used the command Boolean Can have a value of True or False touch hello_world.py. The fi nal and most important part of String Stores a collection of characters. “Hello setting up the fi le is making it executable. This allows us to run World” is a string code inside the hello_world.py fi le. We do this with the command chmod +x hello_world.py. Now that we have our fi le set up, we can go ahead and open it up in nano, or any text editor of your As well as these main data types, there are sequence types choice. Gedit is a great editor with syntax highlighting support (technically, a string is a sequence type but is so commonly used that should be available on any distribution. You’ll be able to we’ve classed it as a main data type): install it using your package manager if you don’t have it already. List Contains a collection of data in a specifi c order [