Update: These instructions are over a year old, though they may still work for you.
See the “Install Python” page for the most recent instructions.
On Snow Leopard you won’t install Xcode via the App Store, you’ll have to download it from Apple.
After I’d helped my friend I found this blog post describing a procedure pretty much the same as below.
Update: If doing all the stuff below doesn’t seem like your cup of tea, it’s also possible to install Python, Num Py, Sci Py, and matplotlib using double-click binary installers (resulting in a much less flexible installation), see this post to learn how.
You will need Apple’s developer tools in order to compile Python and the other installs.
On Lion you can install Xcode from the App Store, on Snow Leopard you’ll have to get an older Xcode from developer.
I use the Xcode editor because I like its syntax highlighting, code completion, and organizer.However, I use hardly any of its features and unless you’re an i OS or Mac developer you probably won’t either.If you prefer another editor it’s possible to get only the libraries and compilers that you need with the Command Line Tools for Xcode.(You’ll need a free Apple ID.) (See also Homebrew is an excellent package manager for Mac OS X that can install a large number of packages.To install it simply launch a terminal and enter Homebrew will install a couple of packages required by Python and then Python itself. Important: You should close your terminal and open a fresh one right now so that it has the updated PATH from the previous section.Otherwise you run the risk of executing the wrong scripts during the rest of these instructions.