At 08:44 PM 2/23/2007 +0100, Thomas Heller wrote:
Well, easy_install makes it snap to install packages that I may or may not use. Nothing is easier than to 'easy_install something-recently-announced', even if I never will use it (after a preliminary look). Often I forget to uninstall the packages again, or promise to do that later. Disk space is cheap.
However, I found that with the ~20 eggs that I have installed the startup time of the Python interpreter (Python2.5, WinXP, measured with 'timeit python -c ""') rises considerably - 2.5 times slower.
This only occurs when the eggs are listed in the easy_install.pth file; if they are moved into a 'normal' pth file this slowdown does not occur, although I can still import the eggs fine.
I assume the additional time is spent by setuptools looking up entry points or whatever?
No. What's happening is that easy-install.pth puts the eggs at the *beginning* of sys.path, in order to ensure that eggs override non-egg packages; this prevents a *huge* amount of complication in sys.path management with respect to detecting conflicts, as well as allowing eggs to be installed that override the standard library (e.g. to allow hotfixing it).
The downside is that this means eggs are searched before the stdlib, slowing down the import of stdlib modules at startup.
The easy fix is to use the "-m" option, which doesn't put the eggs in any .pth file at all -- and removes them if they're there.
IMO this is a critical problem of easy_install... (Imaging how the installed and possibly never used eggs pile up).
How many of these eggs are directories, vs. how many are zipfiles? Zipfiles shouldn't be having so much effect.
Meanwhile, in setuptools 0.7 there will be a completely different way of managing installation locations, and it will not depend on .pth files or on putting eggs first. Instead, it will use direct old-style installation, combined with .egg-info directories for metadata and for installation manifests to support automated uninstallation, upgrades, and integrity verification.