[Python-Dev] New and Improved Import Hooks (original) (raw)

Moore, Paul Paul.Moore@atosorigin.com
Tue, 3 Dec 2002 11:48:29 -0000

(I'm reading python-dev via the web, so this is a combined reply to various posts)

First of all, let me say that I'm interested in imports from zipfiles, as a feature. I don't have any intrinsic reason to prefer a specific implementation over any other. I picked up Jim Ahlstrom's patch and had a look at it simply because it seemed the best way to help.

My view is that import.c is, indeed, very complex and difficult code to follow. I haven't made a significant attempt to do so, taking the view that as Jim's patch basically worked for him, I will just look at updating things to cope with the changes in CVS since his patch was current. (The comments in SF indicate that the patch was nearly accepted as it stood, and just needed updating to match current CVS).

I agree with Just's comments that a cleanup in import.c would be useful. But I'm not in a position to do that, much as I would like it. (One example - "universal newline" support could do with being better localised - I just implemented the 4th copy of a tiny chunk of code to juggle file open modes to support it).

I think that the zipfile patch is close to being acceptable. I don't have a problem if it gets rejected, but can I make a plea

By the way, the zipfile import also implements a cacheing feature for directory lookups. PEP 273 gives more details, including some benchmarks, but the indications are that the cache speeds up normal imports as well as being crucial for zipfile imports (where directory lookups are slow). I can't see how the design of Just's patch would help us implement this cache - maybe he can comment.

Finally, while we're looking at imports and hooks, has anyone considered Gordon McMillan's imputil replacement, as described at http://www.mcmillan-inc.com/iu.html? I've used it to implement a proof-of-concept zipfile import (in Python) before now, and it was pretty simple to use. Maybe this would be a good candidate for the standard library?

Thanks to everyone for the interest and support. Paul.