How to use Environment Variables to set location of file in Python?

[Gonzalo Gonza]

Hello there,
I want to create a txt in system32, but I want to do that using an environment variable.
I want to use an environment variable instead of this:

file = open("C:\\Windows\\system32\\asdfasdf.txt","w")

Because many pc's don't have their %SYSTEMDRIVE% in C:

So, which would be the correct form?
Thank you

[bvdet]

You can determine the value of SYSTEMDRIVE from os.environ['SYSTEMDRIVE'].

[Gonzalo Gonza]

And how it would be?

import os
file = open("os.environ['SYSTEMDRIVE']\\Windows\\system32\\asdfasdf.txt","w")

[bvdet]

I would use:
os.path.join(os .environ['SYSTEMDRIVE'], "Windows/system32/asdfasdf.txt")