# [Tutor] How to get both 2.6 scripts as well as 3.1 scripts to run at command line?

Richard D. Moores rdmoores at gmail.com
Thu Sep 16 11:28:13 CEST 2010

On Thu, Sep 16, 2010 at 00:54, Alan Gauld <alan.gauld at btinternet.com> wrote:
>
> "Richard D. Moores" <rdmoores at gmail.com> wrote
>
>> Some of the scripts written for 2.6 use libraries not yet available for 3.x.
>> So I want to know not how to modify them, but how to run them at the command
>> line.
>
> Install 2.x.
> This is why we keep recommending that beginners stick with 2.x.
> Its why the 2.x line has not died out and still gets new releases.
>
> Eventually the library owners will port their code but until then
> you need to use the version of python they are written for.
> You cannot mix them reliably.

I should have stated that I have 2.6, 2.7, and 3.1  installed. The
scripts are in 2 groups. One written in 2.6, the other in 3.1. Most
run fine in the appropriate version of IDLE, or in Wing when I change
between c:\Python31\pythonw31.exe and c:\Python26\python.exe .  But
some 2.6 scripts must be run at the command line. All the 3.1 scripts
do, but not the 2.6's.

So my problem and question is how to set up a command line that will
run not just the 2.6 scripts that must be run there, but all of them.

And you know what? In thinking through again what my problem was, I
got the idea to try this, and it worked:

==================================================
C:\P26Working\Finished>c:\Python26\python.exe solveCubicEquation.py
Enter real coefficients a,b,c: 3,2,1
a is 3.0
b is 2.0
c is 1.0
equation is (x**3) + (3.000000*x**2) + (2.000000*x) + (1.000000) = 0

roots: [(-2.3247179572447463+0j),
(-0.33764102137762697+0.56227951206230142j),
(-0.33764102137762697-0.56227951206230142j)]

After ignoring very small root.real and root.imag,
and rounding to 4 significant figures:

root1 is -2.325
root2 is -0.3376+0.5623j
root3 is -0.3376-0.5623j

Press Enter to solve another; n to close:
==============================================

So thanks to all for trying to help. Without your tries I wouldn't
have figured it out!

Dick