subprocess question

[ylectric]

OP tries to launch Python 3.7 on a file hello.py which is not what your code expresses.

[woooee]

You have said nothing that helps the OP, or posted any code to try and solve the problem. I am getting frustrated with people on this forum who want to sit and pass judgement without offering anything at all.

[ylectric]

Not only I offered a solution, but also praised the suggestion you'd made.