How to execute a code from another script and pass arguments - python-3.x

Question

I have a python code try.py which has to execute another one called prova.py.
I do it as folows and it works:
exec(open("prova.py").read())
Now, I have some variables I need to pass to prova.py, and I did it as follows according to what found here: https://www.geeksforgeeks.org/exec-in-python/
var = {key:val for key, val in enumerate(lista_gp_todict)}
exec(open("prova.py").read(), var)
try.py does not give error which means the way I write exec now is still correct in terms of syntax, but in the moment this exec runs it gives error in prova.py:
NameError: name 'var' is not defined
which mean that the code prova.py which has inside the variable var does not recognise it, like it was not declared. In fact var is not declared into prova.py because if I pass it I assume it already there.
What am I doing wrong?
PS: my OS is windows

Answer 1

Typically you would call another script with the subprocess module.
subprocess.run() accepts an iterable of strings as arguments to be run as a separate process. You can use the arguments exactly as you would call them from command line.
subprocess.run(['python', 'prova.py', my_argument])
Since you wish to pass a dict to your script, you can do so by first serializing to json, which is just a nice way of saying "convert it to a string".
Since var is your dict you can do so like.
subprocess.run(['python', 'prova.py', json.dumps(var)])
And then deserialize or "convert back to a dict" in prova.py.
var = json.loads(sys.argv[1])
Alternatively, you could import prova.py if all you intend to use from it are functions, classes, or variables.
For example, if prova.py contains:
# prova.py
def my_func(var):
# do some stuff to var
You can then do this in your main script:
import prova
var = {key:val for key, val in enumerate(lista_gp_todict)}
prova.my_func(var)