Get environment variable for current user and for all users in Python

I don't think you can figure it out using standard Python means like os.environ. The only way to get user and system variables on Windows is to use registry, you can find more here:

HKEY_CURRENT_USER\Environment

System Variables

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment

User variables

You need to access registry with Python to get them.