[Python] PYTHONPATH on Mac 10.5

Hi Vincent,
There are different instructions on how to set PYTHONPATH because it
solves a problem (how to organize one's Python modules) that has more
than one solution. It's sort of like asking "How should I organize my
email?" Different strokes for different folks.

Me, I don't use PYTHONPATH at all. Most of the stuff I want to import
is already available in site-packages. If not, I can add a .pth file
to site-packages that tells Python where to find the source. You can
read about .pth files here:
http://docs.python.org/library/site.html

Yikes! Your scripts won't be too portable then, will they? I'm on OS X
10.5 and I don't have a directory like that. A common, more portable
alternative is this:

#!/usr/bin/env python

That relies (obviously) on /usr/bin/env being present which means that
your scripts won't work on Windows machines, for instance. But it's a
whole lot more portable than what you've got now. You don't need a
shebang line at all if you're willing to launch your scripts by typing
`python foo.py` at the command line. That will merely execute
whichever python appears first in your path. I used to always use the /
usr/bin/env shebang line that I described above, but I do so less
often now. It's one less dependency to deal with.

So, in short, PYTHONPATH doesn't need to be set at all, and you can
switch the shebang line to this:

#!/usr/bin/env python

Or do away with it entirely.

This isn't a complete answer but has it been at least somewhat helpful?

Cheers
Philip

+1 for site packages and standard shebang, still lets you launch with
python first followed by .py file or <big long path to a specific
python> followed by .py file

also for some clues, just open up a terminal in your Mac OS X computer
and check out your exports your PATH will be different depending on
all the software and development environments you may or may not be
using on your Mac, in particular:

declare -x PATH="/opt/local/bin:/opt/local/sbin:/Library/Frameworks/Python.framework/Versions/Current/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin"

declare -x PYTHONSTARTUP="/Users/pythonnutter/.pythonstartup"

for the ultra curious, my custom python startup:

$cat .pythonstartup
# python startup file
import readline
import rlcompleter
import atexit
import os
# tab completion
readline.parse_and_bind('tab: complete')
# history file
histfile = os.path.join(os.environ['HOME'], '.pythonhistory')
try:
readline.read_history_file(histfile)
except IOError:
pass
atexit.register(readline.write_history_file, histfile)
del os, histfile, readline, rlcompleter



On Windows you don't have much control in standard batch files but the
way I keep my Windows box (at work mind you, none at home)
multi-python'd

is I configure the environment for Framework 2.5.4, and all the path
environment variables are configured for the standard directory and
the scripts subdirectory.

in 25's scripts is go26.bat which just pre-pends the 2.6.1 path on the
head of PATH, and of course a go3.bat that pre-pends in 3.0.1

if you want to get fancy, since there is no pop in batch files that I
know of, you could drop a .py script in to read in PATH, pop off two
entries and modify the environment PATH so you fall back down the tree
(might need some list reversing in there to finish the massaging for
pops)

most times I get by with just exiting the terminal session in windows
and a new cmd session will once again take on the defaults for 2.5.4