[Python-Dev] 2.3 startup speed?

[Jeremy Hylton]

On Fri, 2003-07-11 at 10:16, Fred L. Drake, Jr. wrote:
> Perhaps, but... those imports only happen if it already looks like
> you're running from a build directory, so they don't impact the
> imports for an installed Python.

You are so true.  I just did fresh installs of 2.2.3 and 2.3 to see what
happens when I run from an install Python.

A nice minimal set of imports for 2.2.3:

import site
import os
import posix
import posixpath
import stat 
import UserDict
import copy_reg
import types
import __future__

There are a lot more for 2.3 (and each one costs more).

import zipimport
import site
import os
import posix
import posixpath
import stat
import UserDict
import copy_reg
import types
import warnings
import linecache
import re
import sre
import sre_compile
import _sre
import sre_constants
import sre_parse
import string
import encodings
import codecs
import _codecs
import encodings.aliases
import encodings.iso8859_15

We can blame the extra imports on three new features.

The zip import feature requires the zipimport module.

The warnings feature requires warnings, linecache, and re, where re is
costly -- seven imports in total.  The top-level "import re" was removed
from warnings.py, but it doesn't make any difference.  The routine that
*uses* the re module is called from the top-level of the warnings
module.

The default file system encoding feature requires the encodings and
codecs packages to be loaded.  That's another five imports.

Anyone want to drop warnings and encodings? <0.9 wink>

Jeremy