What is different with Python ?

[Steven D'Aprano]

D H wrote:

> But what you are getting at is more akin to our mental model of what the 
> computer is doing when we write and run a program.  Without a 
> fundamental understanding of memory and addresses, a programmer can make 
> certain mistakes that reveal this lack of understanding.  But that 
> doesn't mean they have to learn about memory management at the very 
> beginning of their instruction.

Finally somebody who gets it :-)

Every home handyman needs to know the difference 
between a claw hammer and a tack hammer and rubber 
hammer, and why you shouldn't use a claw hammer to 
knock dints out of steel sheeting, but they don't need 
to learn them all on the first time they look at a nail.

I'm reminded about the concept "lies for children", 
used by Ian Stewart and Jack Cohen (mathematician and 
biologist respectively) in some of their books. The 
point they make is that much of what we teach each 
other -- even adults -- is "lies for children". The 
Earth is not a sphere, even though we can often get 
away with pretending it is. High and low tides aren't 
caused by the moon. Testosterone doesn't cause 
aggression. DNA is not a blueprint. And adding two 
strings together is not a simple operation, despite 
appearances.

"Lies for children" in this sense are not *bad*, they 
are a necessary step towards a more sophisticated 
understanding. Imagine trying to learn about projectile 
motion if you needed to understand general relativity 
and friction just to get started. Now imagine you are a 
ballistic missile scientist, and you assume that the 
problem of firing a missile from here to there is 
independent of the shape of the Earth's gravitional 
field, air resistance and relativity. You've just 
missed your target by a kilometre. Ooops.

Learning when you can ignore implementation details is 
just as important a skill as learning how to use 
variables. Just as you wouldn't try teaching closures 
to people who haven't yet learnt what a function is, 
you don't want to bog people down with implementation 
details too early -- but if you don't teach them *at 
all*, you are creating second-class programmers who 
will write slow, buggy, hard-to-maintain code.

-- 
Steven.