PyCon: Evangelizing Python

By trade I'm a Kernel/Systems Programmer so most of my work is done in C. However before I fell into that I was determined to be a game developer so I've written a lot of application code in many high level languages. I've developed game engines in C,C++,Java, and C# using opengl, directX, XNA and even did a stint working on an Unreal 3 engine based game before I had to quit due to conflicting with my real job (it eventually got released when they decided to actually hire developers instead of making it a people work on it in their free time project).

Even though UE3 game logic is mostly written in Unreal Script the language itself was checked and some preliminary compilation was done before being cooked and packaged for deployment into the game. The most interesting feature that I found for unreal script was that classes had states and function overloading wasn't just on parameterization but also based on state. You could declare a function onFire in the default state but then also declare the same function in a state called currentlyFiring. Where onFire in the default state would start the gun firing and setup the animations and such calling onFire in the while firing state would endup being a noop for certain weapons to make sure that you couldn't fire during a reload. Alternative if your weapon was in the reloading state and you called onfire again certain weapons would cancel the reload like in the instance of a pump shotgun.

On top of that I've done enterprise work for Java and C# and have done web apps in both. I've been trying to learn ruby as well as python because even though I'm not a fan of weak typed scripting languages more and more is being written in it and standing still just means you get left behind.

One issue I have with python is that every time I've asked for the right way to do something the only thing I get from python advocates is that you're free to do it however you like. Except for the one time I did something which is apparently against the book in a language which from what I can tell is the free love movement of development. I needed to validate the types of data coming in from a json string and to do this I checked if the values I got back matched certain data types which apparently is a big no no in the world of python. Instead I'm supposed to use them as if they were those data types and wait for the world to explode when they aren't and pick up the pieces.

Another is that we see horribly written code which makes its way into the core of Linux systems being written in python. The initial code for all of the Xen services was written in python and it was a horrible mess and horrible to maintain. What did they do? They started transitioning it all into C system services. Python is great in that it makes programming accessible to people who never would have programmed to begin with. However python is also horrible for the same reason.

def check_age(data):
    d = json.loads(data)
    if d['age'] < 18:
        print "You must be 18 or older to continue."
    else:
        print "OK!"

>>> check_age('{"age": 13}')
You must be 18 or older to continue.

>>> check_age('{"age": "13"}')
OK!