不同 python 版本的子流程执行

Question

I have a script which I execute within a python3 virtual environment and inside this script there is a subrocess.Popen command which starts an application that works only with python2. Is there a way to change the environment only for this process such that this subprocess finds python2 only?

So far I have tried the following which haven't work out.

os.environ["PATH"] = "/path/to/python2/bin:"+os.environ["PATH"] 

Answer 1

Easiest solution I found:

venv = os.environ.copy()
venv.update({"PATH": os.environ["PATH"].replace(venv['VIRTUAL_ENV'], 
                     'other/python/version/path')}) # might have to tweak this a bit only


proc2 = subprocess.Popen(["cmd",
                         env=venv,
                         stdout=sys.stdout,
                         stderr=sys.stderr,
                             )