from main_package.sub_package import another_module
# another file is considered as a module
def main_func():
    another_module.greet_user()
"""
In the command line:
cd to where your file is
python3 main_module.py

VOCAB:
Module - when you have a file that contains code, you should generally refer to it as a module
Package - just a folder with python files in it
"""
