[Pythonmac-SIG] (no subject)

[Bob Ippolito]

On May 10, 2005, at 5:14 AM, konrad.hinsen at laposte.net wrote:

> Bob Ippolito writes:
>
>
>> Well, you might think that you have particularly good reasons to use
>> PYTHONPATH, but pth files can do the same thing in a more predictable
>>
>
> My particularly good reason is that I set PYTHONPATH differently in
> different shell environments for testing purposes. Changing links  
> and path
> files is a lot more work.

I use different checkouts (or python interpreters) for different  
environments...

>> way.  Perhaps it should ignore PYTHONPATH, but why?  NOTHING else   
>> does.
>> It targets every single python interpreter in the system, why   
>> should this
>> be any different?
>>
>
> py2app makes a big effort to make the package independent of the  
> particular
> system environment on which it runs. PYTHONPATH is part of the system
> environment.
>
>  From a more pragmatic point of view, I don't see how respecting  
> PYTHONPATH
> could do anyone any good (except people who intentionally modify the
> behaviour of an installed package, but they usually know what they are
> doing), and it can do a lot of harm by executing different code  
> than the
> packager intended.

Well I went ahead and changed the default behavior to ignore PYTHONPATH.

> In the worst case, a system administrator sets PYTHONPATH for whatever
> reason, and the user who clicks on an application doesn't even know  
> about
> it. He reports a crash to the developer who doesn't suspect  
> anything either.

However, I still don't quite agree with you.  There are PLENTY of  
environment variables that you should only set if you know what  
you're doing, and you should only set as a software developer.  The  
DYLD variables come to mind.  Setting PYTHONPATH is a lot like  
setting DYLD_LIBRARY_PATH.  Both have their obscure uses, and both  
will explode in your face if you use them naively.

A system administrator should never, ever, be setting PYTHONPATH.

-bob