Why doesn't Python remember the initial directory?

Mon Aug 20 10:15:37 EDT 2012

2012年8月20日 Roy Smith <roy at panix.com>:
> In article <k0tf8g$adc$1 at news.albasani.net>,
> Walter Hurry <walterhurry at lavabit.com> wrote:
>>> It is difficult to think of a sensible use for os.chdir, IMHO.
>> It is true that you can mostly avoid chdir() by building absolute
> pathnames, but it's often more convenient to just cd somewhere and use
> names relative to that. Fabric (a very cool tool for writing remote
> sysadmin scripts), gives you a cd() command which is a context manager,
> making it extra convenient.
>> Also, core files get created in the current directory. Sometimes
> daemons will cd to some fixed location to make sure that if they dump
> core, it goes in the right place.
>> On occasion, you run into (poorly designed, IMHO) utilities which insist
> of reading or writing a file in the current directory. If you're
> invoking one of those, you may have no choice but to chdir() to the
> right place before running them.
> --
> http://mail.python.org/mailman/listinfo/python-list

I've done quite a lot of system programming as well, and changing
directory is only a source of possible troubles in general.
If I really have to for some reasons I do this
class TempCd:
 """Change temporarily the current directory
 """
 def __init__(self, newcwd):
 self.newcwd = newcwd
 self.oldcwd = getcwd()
 def __enter__(self):
 chdir(self.newcwd)
 return self
 def __exit__(self, type, value, traceback):
 chdir(self.oldcwd)
with TempCd('/tmp'):
 # now working in /tmp
# now in the original
So it's not that hard to avoid problems..