is there any principle when writing python function

[rantingrick]

On Aug 23, 6:59 am, smith jack <thinke... at gmail.com> wrote:
> i have heard that function invocation in python is expensive, but make
> lots of functions are a good design habit in many other languages, so
> is there any principle when writing python function?
> for example, how many lines should form a function?

Everyone here who is suggesting that function bodies should be
confined to ANY length is an idiot. The length of a functions code
block is inconsequential. Don't worry if it too small or too big. It's
not the size that matters, it's the motion of the sources ocean!

A good function can be one line, or a hundred lines. Always use
comments to clarify code and NEVER EVER create more functions only for
the sake of short function bodies, WHY, because all you do is move
confusion OUT OF the function body and INTO the module/class body.

"""Energy can neither be created nor be destroyed: it can only be
transformed from one state to another"""

http://en.wikipedia.org/wiki/Conservation_of_energy
https://sites.google.com/site/thefutureofpython/