[Python-Dev] Startup time (original) (raw)

Just van Rossum just@letterror.com
Tue, 6 May 2003 20:59:02 +0200

Neal Norwitz wrote:

I think amny of the extra stat/open calls are due to zipimports.

I don't have python23.zip, but it's still looking for a bunch of extra files that can't exist (in python23.zip). Perhaps if the zip file doesn't exist, we can short circuit the remaining calls to open()?

I think we should, although I wouldn't know off hand how to do that.

There's still some nice-to-have PEP302 stuff that remains to be implemented, that could actually help solve this problem. Currently there are no real importer objects for the builting import mechanisms: a value of None for a path item in sys.path_importer_cache means: use the builtin importer. If there was a true builtin importer object, None could mean: no importer can handle this path item, skip it. See also python.org/sf/692884. I hope to be able to work on this before 2.3b2.

stat64("/home/neal/local/lib/python23.zip/warnings", 0xbfffebc0) = -1 ENOENT (No such file or directory) open("/home/neal/local/lib/python23.zip/warnings.so", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory) open("/home/neal/local/lib/python23.zip/warningsmodule.so", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory) open("/home/neal/local/lib/python23.zip/warnings.py", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory) open("/home/neal/local/lib/python23.zip/warnings.pyc", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)

You could try editing site.py so it (as it used to) removes path items that don't exist on the file system. Except this probably only helps if you'd do this before os.py is imported, as os.py pulls in quite a few modules. Hm, chicken and egg... Or disable to the code that adds the zipfile to sys.path in Modules/getpath.c, and compare the number of stat calls.

Just