[Python-Dev] PEP 273 - Import from Zip Archives (original) (raw)

James C. Ahlstrom jim@interet.com
Thu, 28 Feb 2002 12:16:05 -0500

Gordon McMillan wrote:

On 28 Feb 2002 at 9:44, James C. Ahlstrom wrote:

The other objection raised at the time was the possible slow down of imports.

imputil was 30 to 40% slower than C import. iu is about 10 to 15% slower under normal usage, but can be faster if you use archives and arrange sys.path intelligently.

I think I can add iu.py as the standard Python importer to my import.c patches. That is, if iu.py can be imported (using C), then it takes over imports. Note that the C code changes to import.c are still required. Also note that iu.py may be in a zip file, and so the import.c changes are still required.

My code uses os.listdir to cache directory contents, but defers its use until the os module can be imported using the C import code.

A win over some threshold of number of hits on that directory; a loss under that threshold.

Exactly correct. It is tradeoff between the OS caching directory hits from fopen() versus using a Python cache and os.listdir(). Dramatic gains are obtained when importing from network file systems, an important case.

JimA