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Date: Fri, 21 Feb 2014 03:36:14 +1100
Subject: Re: Commonly-used names in the Python standard library
From: Chris Angelico <rosuav@gmail.com>
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On Fri, Feb 21, 2014 at 3:26 AM, Marko Rauhamaa <marko@pacujo.net> wrote:
> Chris Angelico <rosuav@gmail.com>:
>
>> Also, what happens if two modules (one of which might be your script)
>> written for different versions both import some third module? Should
>> they get different versions, based on what version tags they use
>> themselves? Compatibility can't be changed that easily. You either run
>> on the new version, or run on the old. Not both.
>
> Shared C libraries face the exact same issue. Java seems pretty good on
> this front as well. When there is a will, there is a way.

Shared C libraries usually do it by linking against a particular
version. That's why you often need to keep multiple versions around.
Once it's all binary code, there's no more compatibility question - it
all runs on the same CPU. With Python code, the module's written to
run on a particular interpreter, and that can't just switch around -
it's like the weird and wonderful life I enjoyed as 32-bit computing
started coming along, and I wanted to call on code that used the other
word length...

ChrisA