On Sep 24, 6:27 pm, Tim Arnold <[EMAIL PROTECTED]> wrote: > I have a bunch of processes to run and each one needs its own working > directory. I'd also like to know when all of the processes are > finished. > > (1) First thought was threads, until I saw that os.chdir was process- > global. > (2) Next thought was fork, but I don't know how to signal when each > child is > finished. > (3) Current thought is to break the process from a method into a > external > script; call the script in separate threads. This is the only way I > can see > to give each process a separate dir (external process fixes that), and > I can > find out when each process is finished (thread fixes that). > > Am I missing something? Is there a better way? I hate to rewrite this > method > as a script since I've got a lot of object metadata that I'll have to > regenerate with each call of the script.
Use subprocess; it supports a cwd argument to provide the given directory as the child's working directory. Help on class Popen in module subprocess: class Popen(__builtin__.object) | Methods defined here: | | __del__(self) | | __init__(self, args, bufsize=0, executable=None, stdin=None, stdout=None, st derr=None, preexec_fn=None, close_fds=False, shell=False, cwd=None, env=None, un iversal_newlines=False, startupinfo=None, creationflags=0) | Create new Popen instance. You want to provide the cwd argument above. Then once you have launched all your n processes, run thru' a loop waiting for each one to finish. # cmds is a list of dicts providing details on what processes to run.. what it's cwd should be runs = [] for c in cmds: run = subprocess.Popen(cmds['cmd'], cwd = cmds['cwd'] ..... etc other args) runs.append(run) # Now wait for all the processes to finish for run in runs: run.wait() Note that if any of the processes generate lot of stdout/stderr, you will get a deadlock in the above loop. Then you way want to go for threads or use run.poll and do the reading of the output from your child processes. Karthik > > thanks for any suggestions, > --Tim Arnold -- http://mail.python.org/mailman/listinfo/python-list
