If you want to run a .py python file from command line and you also want to pass the argument using command line you can use argparse library.
This can be done as below:
import argparse
# Command Line arguments
argp = argparse.ArgumentParser()
argp.add_argument('--my_var', dest="my_var", action="store", type=int, default=5)
params = argp.parse_args()
myvar= params.my_var
print(myvar)
Then you cal run this py file on command line as below
python predict.py –my_var 7
Thanks