On Jan 11, 5:24 pm, Mike Meyer <[EMAIL PROTECTED]>
wrote:
> On Fri, 11 Jan 2008 14:05:11 -0800 (PST) George Sakkis <[EMAIL PROTECTED]>
> wrote:
>
> > I maintain a few configuration files in Python syntax (mainly nested
> > dicts of ints and strings) and use execfile() to read them back to
> > Python. This has been working great; it combines the convenience of
> > pickle with the readability of Python. So far each configuration is
> > contained in a single standalone file; different configurations are
> > completely separate files.
>
> You know, I've been there before. It's kinda neat, but not something
> you really want to put in the hands of most users.
Well, I am almost the only user (of the config file, not the
application) and the few others are developers too so that's not an
issue in this case.
> You can make the syntax cleaner by using classes to hold the values
> instead of nested dicts, etc. That way you don't have to quote the
> names of the values:
>
> class Foo:
> bar = 1
> baz = 2
Actually I am using the dict() constructor instead of literals so it's
as clean as with classes; IMO for nested options it's cleaner than
nested classes:
Env = dict(
PORT = 6789,
KEY = 123456789,
EXE = '/usr/local/lib/myprog',
LD_LIBRARY_PATH = ':'.join([
'/usr/lib',
'/usr/local/lib',
]),
OPTIONS = dict(
n = None,
min = 1,
max = 15000,
)
)
> > ======================
> > # some_config.py
>
> > # master_config.py is in the same directory as some_config.py
> > from master_config import *
>
> > # override non-default options
> > foo['bar']['baz] = 1
> > ...
>
> > ======================
> > # trying to set the configuration:
> > CFG = {}
> > execfile('path/to/some_config.py', CFG)
>
> > Traceback (most recent call last):
> > ...
> > ImportError: No module named master_config
>
> > I understand why this fails but I'm not sure how to tell execfile() to
> > set the path accordingly. Any ideas ?
>
> Manipulate sys.path yourself?
That's what Mitko suggested too, and indeed it works:
import sys, os
def setConfig(configfile):
cfg = {}
syspath = list(sys.path)
try:
sys.path.append(os.path.dirname(configfile))
execfile(configfile, cfg)
finally:
sys.path = syspath
return cfg
However this doesn't look very clean to me. Also it's not thread-safe;
guarding it explicitly with a lock would make it even less clean.
Ideally, I'd like to pass a new path to execfile without modifying the
original (even for the few milliseconds that execfile() wlll probably
take). With modules being singletons though, I don't think this is
possible, or is it ?
George
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