[Tutor] range efficiency

[Dave Angel]

On 05/10/2013 05:19 PM, Jim Mooney wrote:
> If I'm using a variable-dependent range in a for loop, is Python smart
> enough to figure the variable once so I don't have to hoist it up?
>
> That is for c in range(0,x+2), is x+2 figured once or every time
> through the loop? I'm assuming it's once but I like to verify.

It's only done once.

>
> I'll figure this myself once I get an editor I like with a profiler,
> but I'm still trying editors and don't want to spend all my time on
> them. So far I'm in between too simple, overkill, or buggy. And I
> don't want anything that uses Java. I'm allergic to Java ;')
>

You don't need to use a profiler, or an IDE to answer a question like 
this.  A very useful thing is the dis module:

http://pymotw.com/2/dis/index.html
http://docs.python.org/library/dis.html#dis.disassemble

It shows you the output of the Python compiler.  It doesn't take long to 
learn to read the code it displays.

-- 
DaveA