[Python-Dev] Fix import errors to have data (original) (raw)

Phillip J. Eby pje at telecommunity.com
Wed Aug 4 18:16:37 CEST 2004

At 09:53 AM 8/4/04 -0400, Jim Fulton wrote:

Phillip J. Eby wrote:

At 10:01 AM 8/2/04 -0400, Jim Fulton wrote: ..

The point of my proposal is to make it possible without rewriting imports, in versions of Python from 2.2 up. Your proposal would, at least, require canges to the pickle framework. I imagine it would affect other serialization and persistence frameworks as well.

Actually, in the updated interface I've been discussing off-list with a few people, all that would happen is that you'd need to be explicit about what interpreter you use to do the unpickling, if you don't want it to be the current one. E.g.:

result = someInterpreter.call(somePickler.loads, data)

In a framework like ZODB, however, I would assume that if supporting multiple interpreters were desirable, one would change the persistent object ID to include a reference to the {bundle|parcel|product} that originated the object.

In any case, the implementation we're discussing (based on the C multiple interpreter API) should be completely transparent to end user code, to the extent that it should be possible to run two different versions of Zope side by side in the same process -- and that will probably make a nice "stress test" for the implementation when we're done with it. :)

I hope that the end-product of our work will be an implementation of a Python-accessible API for interpreter management, and a PEP covering both that API and how to fix the most problematic aspects of the Python C API for multiple interpreters. (Specifically, additions to the API to allow extensions to manage selected static data as interpreter-specific rather than global, and for ensuring that imports stay interpreter-local when execution crosses interpreter boundaries.) I expect the fixes will be able to be used with versions of Python back to 2.2, which was the version that introduced the necessary base APIs for walking the interpreter and thread state chains.

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