Jamie Chan - Learn Python in One Day and Learn It Well: Python for Beginners with Hands-on Project. The only book you need to start coding in Python immediately

Learn Python in One Day and Learn It Well Python for Beginners with Hands-on Project The only book you need to start coding in Python immediately By Jamie Chan http://www.learncodingfast.com/python Copyright 2014 All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. Preface This book is written to help you learn Python programming FAST and learn it WELL. If you are an absolute beginner in Programming, you'll find that this book explains complex concepts in an easy to understand manner. Examples are carefully chosen to demonstrate each concept so that you can gain a deeper understand of the language. If you are an experienced coder, this book gives you a good base from which to explore Python.

The appendices at the end of the book will also provide you with a convenient reference for some of the commonly used functions in Python. In addition, as Richard Branson puts it: "The best way of learning about anything is by doing". At the end of the course, you'll be guided through a project that gives you a chance to put what you've learned to use. You can download the source code for the project and the appendices at http://www.learncodingfast.com/python . Table of Contents

Welcome to the exciting world of programming. I'm so glad you picked up this book and I sincerely hope this book can help you master the Python language and experience the exhilaration of programming.

Before we dive into the nuts and bolts of Python programming, let us first answer a few questions.

Python is a widely used high-level programming language created by Guido van Rossum in the late 1980s. The language places strong emphasis on code readability and simplicity, making it possible for programmers to develop applications rapidly. Like all high level programming languages, Python code resembles the English language which computers are unable to understand. Codes that we write in Python have to be interpreted by a special program known as the Python interpreter, which well have to install before we can code, test and execute our Python programs. We'll look at how to install the Python interpreter in Chapter 2.

There are also a number of third-party tools, such as Py2exe or Pyinstaller that allow us to package our Python code into stand-alone executable programs for some of the most popular operating systems like Windows and Mac OS. This allows us to distribute our Python programs without requiring the users to install the Python interpreter.

There are a large number of high level programming languages available, such as C, C++, and Java. The good news is all high level programming languages are very similar to one another. What differs is mainly the syntax, the libraries available and the way we access those libraries. A library is simply a collection of resources and pre-written codes that we can use when we write our programs.

If you learn one language well, you can easily learn a new language in a fraction of the time it took you to learn the first language. If you are new to programming, Python is a great place to start. One of the key features of Python is its simplicity, making it the ideal language for beginners to learn. Most programs in Python require considerably fewer lines of code to perform the same task compared to other languages such as C. This leads to fewer programming errors and reduces the development time needed. In addition, Python comes with an extensive collection of third party resources that extend the capabilities of the language.

As such, Python can be used for a large variety of tasks, such as for desktop applications, database applications, network programming, game programming and even mobile development. Last but not least, Python is a cross platform language, which means that code written for one operating system, such as Windows, will work well on Mac OS or Linux without making any changes to the Python code. Convinced that Python is THE language to learn? Lets get started...

Before we can write our first Python program, we have to download the appropriate interpreter for our computers. Well be using Python 3 in this book because as stated on the official Python site Python 2.x is legacy, Python 3.x is the present and future of the language. In addition, Python 3 eliminates many quirks that can unnecessarily trip up beginning programmers.

However, note that Python 2 is currently still rather widely used. Python 2 and 3 are about 90% similar. Hence if you learn Python 3, you will likely have no problems understanding codes written in Python 2. To install the interpreter for Python 3, head over to https://www.python.org/downloads/ . The correct version should be indicated at the top of the webpage. Alternatively if you want to install a different version, scroll down the page and youll see a listing of other versions. Alternatively if you want to install a different version, scroll down the page and youll see a listing of other versions.

Click on the release version that you want. Well be using version 3.4.2 in this book. Youll be redirected to the download page for that version. Scroll down towards the end of the page and youll see a table listing various installers for that version. Choose the correct installer for your computer. The installer to use depends on two factors: 1.

The operating system (Windows, Mac OS, or Linux) and 2. The processor (32-bit vs 64-bit) that you are using. For instance, if you are using a 64-bit Windows computer, you will likely be using the "Windows x86- MSI installer". Just click on the link to download it. If you download and run the wrong installer, no worries. You will get an error message and the interpreter will not install.

Simply download the correct installer and you are good to go. Once you have successfully installed the interpreter, you are ready to start coding in Python.

Well be writing our code using the IDLE program that comes bundled with our Python interpreter. To do that, lets first launch the IDLE program. You launch the IDLE program like how you launch any other programs. For instance on Windows 8, you can search for it by typing IDLE in the search box.

Once it is found, click on IDLE (Python GUI) to launch it. Youll be presented with the Python Shell shown below. The Python Shell allows us to use Python in interactive mode. This means we can enter one command at a time. The Shell waits for a command from the user, executes it and returns the result of the execution. After this, the Shell waits for the next command.

Try typing the following into the Shell. The lines starting with >>> are the commands you should type while the lines after the commands show the results.
>>> 2+3 >>> 3>2 True >>> print (Hello World) Hello World When you type 2+3 , you are issuing a command to the Shell, asking it to evaluate the value of 2+3. Hence, the Shell returns the answer 5. When you type 3>2 , you are asking the Shell if 3 is greater than 2. The Shell replies True . Finally, print is a command asking the Shell to display the line Hello World .

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