Python automatically compiles a python script before running it, the first time the script runs it will create a .pyc in the same directory as the .py file which will then be used if the script is run again to save time by not having to re-compile the code.
11/2023 (v.115)- Modified the offset values in the internal signature from null to 0 as part of a project to match PRONOM data with the xsd standard. Internally researched.