Multiple versions of Python coexisting in the same OS

[Mark Lawrence]

On 24/07/2010 04:17, Edward Diener wrote:
> Are there any documents about multiple versionsof Python coexisting in
> the same OS ( Windows in my case ) and what pitfalls to look out for ? I
> have already run into a number of them. I installed Python 2.7 and 3.1.2
> into completely folders, but immediately ran into serious problems
> executing a Python script.
>
> The first problem is that just invoking Python will start whichever
> version is first in the PATH, and this is true from the command line or
> internally in a Python script.
>
> The second problem is that invoking a script ( some xxx.py ) will start
> whichever version of Python is associated with the .py extension.
>
> The third problem is if some software expects its scripts, which it puts
> in some Python subdirectory to be in the PATH.
>
> There may be other considerations but overall having to versions
> coexisting has turned out to be a big headache involving both changes in
> the PATH and in the .py association.
>
> Does anybody know of other things to look out for ?

I found this only yesterday and found it extremely helpful, find the 
post by Gabriel Genellina.

http://www.eggheadcafe.com/software/aspnet/35716114/maintain-2-versions-of-py.aspx

HTH.

Mark Lawrence