python - os.getenv and os.environ don't see environment variables of my bash shell

Solution 1:

Aha! the solution is simple!

I was setting variables with plain $ A=5 command; when you use $ export B="foo" everything is fine.

That is because export makes the variable available to sub-processes:

  • it creates a variable in the shell
  • and exports it into the environment of the shell
  • the environment is passed to sub-processes of the shell.

Plain $ A="foo" just creates variables in the shell and doesn't do anything with the environment.

The interpreter called from the shell obtains its environment from the parent -- the shell. So really the variable should be exported into the environment before.

Solution 2:

Those variables (parameters in bash terminology) are not environment variables. You want to export them into the environment, using export or declare -x. See the bash documentation on environment.