[Distutils] desirability of multiple, divergent Python instances (was: shebang line modified by setuptools)

[Ben Finney]

Greg Ewing <greg.ewing at canterbury.ac.nz> writes:

> Gael Varoquaux wrote:
> > a second Python needs to be installed on top of the system Python
> > to add modules to it.
> 
> Maybe the system should come with two pythons installed, one for use
> by the system and the other for users to add things to. Or at least
> be set up so that it appears that way -- they might share files
> under the hood.

I can't see how this is a good idea. I've seen it mentioned multiple
times in this thread, but without justification.

It's my position that the Python instance one uses for development
should diverge as little as possible from the default system instance.
Otherwise one is actively pursuing a recipe for dependency failures
when one eventually deploys the result.

Yes, there should be a way to deploy the code one is actively
developing and testing to some location that will not affect the rest
of the operation of the system. That is a far cry from asking that
there should be multiple, divergent Python instances on the system.

The further step of saying that the operating system should not use
the same Python instance as a "user" on the system (and note that the
line between those is far from clear), but instead should use some
Python instance that behaves differently from every other use of
Python on the system, seems like an even worse proposition, for the
above reasons.

Help me understand, please.

-- 
 \        "Most people don't realize that large pieces of coral, which |
  `\       have been painted brown and attached to the skull by common |
_o__) wood screws, can make a child look like a deer."  -- Jack Handey |
Ben Finney