Change the environment variable for python code running

python程序运行中改变环境变量:

Trying to change the way the loader works for a running Python is very tricky; probably OS/version dependent; may not work. One work-around that might help in some circumstances is to launch a sub-process that changes the environment parameter using a shell script and then launch a new Python using the shell.

So, before the python code is executed, the env var is loaded.

Ref: https://stackoverflow.com/questions/1178094/change-current-process-environments-ld-library-path

But how to launch a sub-process that changes the environment parameter:

You can ref: https://stackoverflow.com/questions/8365394/set-environment-variable-in-python-script?rq=1