what i would like to add to subprocess.Popen()

[Skaperen]

OK. i think that is what i wanted as chdir=. apparently my thinking gave it some other semantics as i scanned the documentation originally. this time it looks right. the future may still have a need for other settings. maybe they can be done in the parent or maybe not. best would be a function, maybe with args. then you can play dangerously, like root changing effective user (BTDT in C). for a current project, cwd= is good enough. it is a function to run a pipeline of commands, and i chose to use the same argument cwd= to be consistent with Popen() and maybe others.