Goplat added the comment:
Zipping up the Lib directory from the python source (1735 files) as a test, it
took on average 0.10 sec to read the zip before, 0.04 sec after.
(To test the time taken by zipimport isolated from other startup costs, instead
of actually getting the zip in the import
New submission from Goplat :
Reading the list of files in a .zip takes a while because several seeks are
done for each entry, which (on Windows at least) flushes stdio's buffer and
forces a system call on the next read. For large .zips the effect on startup
speed is noticeable, being pe
