how to run a py file using a specific interpreter code example

Example 1: how to run a python script

# Save the script in a file with .py extension
# run the script using the below command
python fileName.py

Example 2: python if run in terminal

import sys
if sys.stdin.isatty():
    # running interactively
    print "running interactively"
else:
    with open('output','w') as f:
        f.write("running in the background!\n")