Why doesn't os.system('set foo=bar') work?

Question

Possibly a stupid question: Why can't I set an environment variable with this?

os.system('set foo=bar') # on windows

I'm aware of os.environ, and that works for me. I'm just confused about why the former doesn't work.

Answer 1

See the discussion here -- export and set are both shell commands, and whether on Windows or Unix, they're still inevitably being addressed to a child process running the shell (be it bash, cmd.exe, whatever) and so bereft of any further action when that child process terminates (i.e., when os.system returns to the caller).