How to use export with Python on Linux
Question: I need to make an export like this in Python :

    
    
    # export MY_DATA="my_export"
    

I've tried to do :

    
    
    # -*- python-mode -*-
    # -*- coding: utf-8 -*-
    import os
    os.system('export MY_DATA="my_export"')
    

But when I list export, "MY_DATA" not appear :

    
    
    # export
    

How I can do an export with Python without saving "my_export" into a file ?


Answer: `export` is a command that you give directly to the shell (e.g. `bash`), to
tell it to add or modify one of its environment variables. You can't change
your shell's environment from a child process (such as Python), it's just not
possible.

Here's what's happening with you try `os.system('export
MY_DATA="my_export"')`...

    
    
    /bin/bash process, command `python yourscript.py` forks python subprocess
     |_
       /usr/bin/python process, command `os.system()` forks /bin/sh subprocess
        |_
          /bin/sh process, command `export ...` changes local environment
    

When the bottom-most `/bin/sh` subprocess finishes running your `export ...`
command, then it's discarded, along with the environment that you have just
changed.

