Depends what you mean by using sys.argv. I can call this script from the command line with an arguement or call the run() method directly from UiPath with the text argument. This is the python code:
import sys
def run(text):
return " Hi " + text
if __name__ == "__main__":
run(sys.argv[1])
and this is the invoke python activity to call the script:
The output is as expected, “Hi Bob”: