使用Python更改环境变量

Question

I am having a problem with the environment variables in python. How do I get python to export variables to the parent shell?

I am using ubuntu, python 2.7.4

I get this:

$ python
>>> import os
>>> os.environ
{'HOME':'~'}
>>> os.environ['foo']='bar'
>>> os.environ
{'HOME':'~','foo':'bar'}
>>> quit()
$ echo $foo
    # Place #1
$ python
>>> import os
>>> os.environ
{'HOME':'~'}    # Place #2
>>> 

My expected output is:

• At Place #1: bar
• At Place #2: {'HOME':'~','foo':'bar'}

Thanks

Answer 1

Environment variables set in a child process (eg python) do not affect the parent process.

It's a one-way street; if this could be done it would be very easy to exploit shells! The environment variables must be set in the parent process itself. This restriction is enforced by the operating system and is not specific to Python.

Note that sourcing a file in a shell (eg . script.sh ) doesn't create a new process; but there is no way to "source" Python files.