Files with the Python extension cannot be opened on the PC, what should I do?

Question

Python

Everything was great before.
There are no errors in the code, everything is checked.
All files with this extension do not open, even those that used to work. (They open on another PC)
Sorry if this is a stupid question, I just haven't come across this before.

Answer 1

<full path to the python interpreter> <file name>.py
full path to the python interpreter can be written in PATH
But it is better to read about virtual environments, use them