It's better to not expect that python is named python for example for me it's called python3.8.

You might be able to call the functions directly.

Does python3 also work?

You can replace the interpreter command call with an import to that and using the function. Look in BF-it.py

I wouldn't recommend renaming that file since the dash is part of the name

I mean you should use

import Interpreter
from Compiler import Compiler

Compiler.compile(code)
# and
Interpreter.brainfuck(code)

The command to run the BF file MUST be a command so subprocess.Popen() can run it

Please import the interpreter function and use it, instead of calling subprocess. There is an example in BF-it.py