how to run another python file without stopping the firsy py file code example

Example 1: run py file in another py file

os.system('python my_file.py')

Example 2: 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 3: how to run python in terminal

#For Python 3:
$ python3 helloworld.py
#For Python 2:
$ python helloworld.py

Example 4: to run python script in terminal i want to type python insted of python3

$ python --version
Python 2.7.6
$ python3 --version
Python 3.4.3
$ alias python=python3
$ python --version
Python 3.4.3