Take a look at the following simple example:
import sys
secret = "My secret"
print(f"From argv: {sys.argv[1]}\n")
print(f"From code: {print(secret)}")
If you run it with python test.py print\(secret\)
or python test.py "print(secret)"
the result is:
From argv: print(secret)
My secret
From code: My secretNone
The argument is simply treated as a string, it is not executed. However, I am not 100 % sure there is no way to force Python to somehow execute it. I am also not sure what would happen if the data came from some another input, like socket for instance.