How similar are the commands for Linux in python

Answer 1

As long as you don't use librairies (which can take the form of compiled python files in .pyc) and don't use system calls (using for example the os.system() function), your python program should be usable on both systems.
The line Met174 refers to is the "shebang", in the form of #!/usr/bin/python which is used by bash to know where the python interpreter is located.

Answer 2

Some moments in this book
Mark Summerfield : "Programming in Python 3"

For example, it is necessary to add 1 line for Unix systems, the program became executed