How do you check what version of Python is running your script?

If you want to check you python version that running you script. You can use sys.version

import system
print(sys.version)

The output

3.9.0 (tags/v3.9.0:9cf6752, Oct 5 2020, 15:34:40) [MSC v.1927 64 bit (AMD64)]

Also
use sys.version_info to know more

The output

sys.version_info(major=3, minor=9, micro=0, releaselevel='final', serial=0)