Chapter 12

Restore Points

As you work your way through the Alien Invasion project, you’ll develop a number of files that work together to create a functioning game. If you make an error somewhere, it can be difficult to know exactly where things went wrong. There are several restore points available for this chapter. You can use these restore points in two ways:

There are three restore points available for Chapter 12:

Installing Pygame

Pygame is usually straightforward to install, but it can get tricky depending on your operating system and the version of Python you have installed. These instructions can help you get Pygame installed quickly, so you can focus on building games.

Pygame on Linux

Python 2.7

If you’re using your system’s default version of Python 2.7, you can install Pygame using the package manager:

$ sudo apt-get install python-pygame

To make sure the installation worked correctly, start a Python terminal session and try to import Pygame:

$ python
>>> import pygame

If you don’t see an error message, you’re ready to start building Alien Invasion.

Python 3

Setting up Pygame for Python 3 is a two-step process; first you’ll install some packages that Pygame depends on, then you’ll download and install Pygame.

Run the following commands to install the packages required to run Alien Invasion. (If you use a command such as python3.5 on your system, replace python3-dev with python3.5-dev):

$ sudo apt-get install python3-dev mercurial
$ sudo apt-get install libsdl-image1.2-dev libsdl2-dev libsdl-ttf2.0-dev

If you want to enable some more advanced functionality in Pygame such as the ability to add sounds, you can also install the following libraries:

$ sudo apt-get install libsdl-mixer1.2-dev libportmidi-dev
$ sudo apt-get install libswscale-dev libsmpeg-dev libavformat-dev libavcodec-dev
$ sudo apt-get install python-numpy

You’ll need pip for the next step; if you haven’t set up pip yet, see the instructions for seting up pip. Enter the following to install Pygame:

$ pip install --user hg+

The output will pause for a moment, informing you which libraries were found. Press Enter, even if there are some libraries missing. You should see a message that Pygame installed successfully. To confirm the installation was successful, start a Python terminal session and try to import Pygame by entering the following:

$ python3
>>> import pygame

If you see no error messages, you’re ready to start working on Alien Invasion!

Pygame on OS X

You’ll need Homebrew to install some packages that Pygame depends on.

To install the libraries that Pygame depends on, enter the following:

$ brew install hg sdl sdl_image sdl_ttf

This installs the minimum number of packages needed to run Alien Invasion. If you want Pygame to have a little more functionality such as working with sound, you can install two additional libraries:

$ brew install sdl_mixer portmidi

You’ll need pip to install Pygame. Once you have pip set up correctly, issue the following command:

$ pip3 install --user  hg+

To confirm the installation, start a Python terminal session and try to import Pygame:

$ python3
>>> import pygame

If this works, you’re ready to start building Alien Invasion!

Pygame on Windows

To install Pygame on your version of Windows, find a Windows installer at that matches the version of Python you’re running. If you don’t see an appropriate installer listed at Bitbucket, check

Once you’ve downloaded the appropriate file, run the installer if it’s a .exe file.

If you have a file ending in .whl, copy the file to your project directory. You’ll need pip set up, so if you haven’t done that yet do so now. Then open a command window, navigate to the folder that you copied the installer to, and use pip to run the installer:

> python -m pip install --user pygame-1.9.2a0-cp35-none-win32.whl

You can test if the installation was successful by starting a new Python terminal session and trying to import Pygame:

> python
>>> import pygame

If this works, you’re ready to start building Alien Invasion!