Part I Of This Course teaches you the basic concepts

you’ll need to write Python programs. Many of

these concepts are common to all programming

languages, so they’ll be useful throughout your life

as a programmer.

In Chapter 1 you’ll install Python on your computer and run your first

program, which prints the message Hello world! to the screen.

In Chapter 2 you’ll learn to store information in variables and work

with text and numerical values.

Chapters 3 and 4 introduce lists. Lists can store as much information

as you want in one variable, allowing you to work with that data efficiently.

You’ll be able to work with hundreds, thousands, and even millions of values

in just a few lines of code.

In Chapter 5 you’ll use if statements to write code that responds one

way if certain conditions are true, and responds in a different way if those

conditions are not true.

Chapter 6 shows you how to use Python’s dictionaries, which let you

make connections between different pieces of information. Like lists, dictionaries

can contain as much information as you need to store.

In Chapter 7 you’ll learn how to accept input from users to make your

programs interactive. You’ll also learn about while loops, which run blocks

of code repeatedly as long as certain conditions remain true.

In Chapter 8 you’ll write functions, which are named blocks of code

that perform a specific task and can be run whenever you need them.

2 Part I

Chapter 9 introduces classes, which allow you to model real-world

objects, such as dogs, cats, people, cars, rockets, and much more, so your

code can represent anything real or abstract.

Chapter 10 shows you how to work with files and handle errors so your

programs won’t crash unexpectedly. You’ll store data before your program

closes, and read the data back in when the program runs again. You’ll learn

about Python’s exceptions, which allow you to anticipate errors, and make

your programs handle those errors gracefully.

In Chapter 11 you’ll learn to write tests for your code to check that

your programs work the way you intend them to. As a result, you’ll be able

to expand your programs without worrying about introducing new bugs.

Testing your code is one of the first skills that will help you transition from

beginner to intermediate programmer

The purpose of this Course is to make you a good programmer in general

and a good Python programmer in particular. You’ll learn efficiently and

adopt good habits as I provide you with a solid foundation in general programming

concepts. After working your way through Python Crash Course,

you should be ready to move on to more advanced Python techniques, and

your next programming language will be even easier to grasp.

In the first part of this book you’ll learn basic programming concepts

you need to know to write Python programs. These concepts are the same

as those you’d learn when starting out in almost any programming language.

You’ll learn about different kinds of data and the ways you can store

data in lists and dictionaries within your programs. You’ll learn to build

collections of data and work through those collections in efficient ways.

You’ll learn to use while and if loops to test for certain conditions so you

can run specific sections of code while those conditions are true and run

other sections when they’re not—a technique that greatly helps to automate

processes.

You’ll learn to accept input from users to make your programs interactive

and to keep your programs running as long as the user is active.

You’ll explore how to write functions to make parts of your program

reusable, so you only have to write blocks of code that perform certain

Introduction xxxi

actions once, which you can then use as many times as you like. You’ll then

extend this concept to more complicated behavior with classes, making fairly

simple programs respond to a variety of situations. You’ll learn to write programs

that handle common errors gracefully. After working through each

of these basic concepts, you’ll write a few short programs that solve some

well-defined problems. Finally, you’ll take your first step toward intermediate

programming by learning how to write tests for your code so you can

develop your programs further without worrying about introducing bugs.

All the information in Part I will prepare you for taking on larger, more

complex projects.

In Part II you’ll apply what you learned in Part I to three projects. You

can do any or all of these projects in whichever order works best for you. In

the first project (Chapters 12–14) you’ll create a Space Invaders–style shooting

game called Alien Invasion, which consists of levels of increasing difficulty.

After you’ve completed this project, you should be well on your way to

being able to develop your own 2D games.

The second project (Chapters 15–17) introduces you to data visualization.

Data scientists aim to make sense of the vast amount of information

available to them through a variety of visualization techniques. You’ll

work with data sets that you generate through code, data sets downloaded

from online sources, and data sets your programs download automatically.

After you’ve completed this project, you’ll be able to write programs that

sift through large data sets and make visual representations of that stored

information.