It's somewhat difficult to find instructions on how to successfully install Pygame for Python 3 on Yosemite. The front page of the Pygame website has a link which appears to point to installation instructions, but it is broken.
Fortunately, someone posted these instructions on the Pygame wiki:
Firstly, ensure you have the Apple Xcode command line tools installed:
xcode-select --install
Install XQuartz from http://xquartz.macosforge.org/landing/. Restart your computer so the newly installed XQuartz is used.
Make sure you have homebrew installed:
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Ensure the homebrew-installed binaries take precedence over system binaries in your $PATH
# in ~/.bash_profile
# Homebrew binaries now take precedence over Apple defaults
export PATH=/usr/local/bin:$PATH
Use homebrew to install Python3 and Pygame dependencies, as well as Mercurial (hg), which we need to install Pygame from Bitbucket:
brew install python3 hg sdl sdl_image sdl_mixer sdl_ttf portmidi
Install Pygame from Bitbucket:
pip3 install hg+https://bitbucket.org/pygame/pygame
