> Well, that stddev function could be much less verbose: Sure, it could, but I was demonstrating what it looked like without the use of functions. Your exampl

> Well, that stddev function could be much less verbose: Sure, it could, but I was demonstrating what it looked like without the use of functions. Your example proves my point just as mine does: sum(), like mean() or variance() in my example, is just a simple function, the kind that I'm arguing for. The fact that it's built into Python (rather recently, I note) doesn't change that fact or reduce the impact of the argument. Your example simply goes one step down the path, and mine goes further. > To me that's easier to read than jumping back and forth between multiple function definitions. You don't have to jump back and forth between function definitions. Let's say you don't know what the standard deviation is, but you know what the mean is. You can look at the definition of stddev() and see, "Ah, it's clearly the sqrt() of the variance. What's the variance? Ah, it's the sum of the squares of difference between each element and the mean." You know what the mean() does (its name is pretty clear) and you know what sum() and square() do, so you never have to look at those functions. Someone else who knows what the variance is would never have to look that deep. When someone is reading the stddev() in my example, he doesn't have concern himself with implementation details of functions he already understands. When someone is reading yours, he has to at least read how the mean is calculated. He can't avoid it--it's right there. > Of course, if you need the mean or variance independently then your way is better. You almost certainly will in any case where you're using the standard deviation, but that's just an artifact of the example. Other advantages of using small, simple functions like in my example: * More reusable (as you noted) * More easily testable. * More easily comprehensible (as I showed above) * More easily documented (especially in a language like Python with its docstring support) * More conceptual abstraction