Multiple versions of Python coexisting in the same OS

[Thomas Jollans]

On 07/25/2010 09:19 PM, Edward Diener wrote:
> On 7/25/2010 10:03 AM, Thomas Jollans wrote:
>> On 07/25/2010 02:46 PM, Edward Diener wrote:
>>> The problem with this is that you forget that a script can invoke Python
>>> internally. So whether one uses the console or file association method
>>> of invoking Python externally, any already written script can use either
>>> internally.
>>
>> Maybe it's just me, but I think that a script that does this is quite
>> simply badly written: it *will* break on systems that have multiple
>> Python versions.
> 
> Whether it is badly written or not in your opinion it is legal and
> happens all the time. Are you going to refuse to use any script, no
> matter for what library or for what purpose, that internally invokes
> Python either through a 'python' command or through a file with a Python
> extension ? And how would you find out if a script did this or not ? Are
> going to search every script in every distribution and library to
> determine if it does this ? And when you find out a script does this,
> what will you do ?
> 
> Be real. saying you do not like scripts that internally invoke Python
> does not solve anything if you have multiple coexisting versions of
> Python installed.

I doubt many scripts do it. The fact of the matter is: many systems have
multiple Python versions installed in parallel, and it probably will
break somewhere, which will get noticed, and probably fixed.

If a script uses sys.executable instead of "python", there is no
problem, at all.