Sending automatic emails to my address book python

This is for education and is also incredibly nooby

I want to know how to send out bulk email to people in my "address book" by address book I mean, when you click "compose" in gmail then type in a letter a whole bunch of people will pop up. Those are the people in my "address book".

So my plan was to fetch a whole bunch of my contacts, arrange them into text files like "A names" so Adam, Alex and Arnold go in that file. Once those have all been organised I should just be able be able to feed that to a for loop which can send an email to each address.

I know how to send a single email with an inputted address, I just need a way to automatically get those addresses. I would be using G-mail for all this and all the addresses would be gmail