Python: Is it possible to change the Windows comma

问题:

I'm using os.system() to do Windows command line shell executions. I would like to change the Windows cmd current directory. Here's one way of doing it:

os.chdir('newPath')

But chdir() will also change the actual Python current working directory. I don't want to change the actual Python working directory because I want other parts of my script to run in the original current working directory. What I want to change is only the Windows cmd current working directory. In other words: I want os.system() commands to run in one current working directory (Windows cmd current working directory) while anything else should run in another current working directory (the actual Python current working directory).

Here's another try to change only the Windows cmd current directory:

os.system('cd newPath')

However, that obviously doesn't work since right after the execution of the cd newPath command the Windows cmd current directory is reset (because I won't use the same Windows command shell in the next call to os.system()).

Is it possible to have a separate current working directory for the Windows cmd shell? (separate from the actual current working directory).

回答1:

The subprocess module is intended to replace os.system.

Among other things, it gives you subprocess.Popen(), which takes a cwd argument to specify the working directory for the spawned process (for exactly your situation).

See: http://docs.python.org/library/subprocess.html

Example usage replacing os.system:

p = subprocess.Popen("yourcmd" + " yourarg", shell=True, cwd="c:/your/path")
sts = os.waitpid(p.pid, 0)[1]

回答2:

If it only has to work on Windows, one way might be:

os.system('start /d newPath cmd')

回答3:

When you use os.system, you're not reusing the same command shell, but spawning a new one for each request. This means that you can't actually expect changes in it to propagate between invocations.

You could write a wrapper though, that will always change to the directory you want before launching the command.