I'm not a native english speaker, so sometimes I need to refresh my memory as to the exact meaning of a word. In this case the exact difference between complex and complicated.
I found an english.stackexchange.com page with some nice answers. According to the first answer:
- Complex is about the number of parts. The more (different) parts, the more complex.
- Complicated is about how hard/difficult something is.
Another answer pointed at the relevant part of the Zen of Python:
Simple is better than complex. Complex is better than complicated.
So when programming, you can divide up a task or problem into separate parts. The more parts, the more complex. Simple is better than complex, so don't add too many parts if you don't need them.
On the other hand, if you want to do everything in one part, it might end up being too difficult, too complicated. Making it more complex (more parts) is better in that case.
It is a trade-off. And it takes experience and a bit of Fingerspitzengefühl to make the right trade-off.
How to learn it? Talk with more experienced programmers is one way. Another way is to explicitly review your programs yourself with those two lines from the Zen of Python. I'll show them here again to drive them home:
Simple is better than complex. Complex is better than complicated.
Ask yourself questions like this:
Do I still understand my own program? Did I make it too complicated?
Did I split it up enough? Or are there 400-line functions that I might better cut up? Into a more complex, but clearer, whole?
Well-separated parts might make reasoning about your complicated problem easier.
Did I split everything up too much? Do you have more parts than your brain can handle?
Your brain's CPU has room for some 7 variables. Too many parts might make it impossible for you to work on your own code :-)