I am trying to set up an automated email sending script. I am using the email module and the EmailMessage object from the email.message module and am sending the email using the smtplib module. I would like to be able to attach a .pdf file to an email but the documentation for the add_attachment() method for EmailMessage() is not very helpful and I'm not even sure I should be using it. 
Here is what I have so far with irrelevant information removed:
import time
import smtplib
from email.message import EmailMessage
FROM = 'my email'
s = smtplib.SMTP('smtp.gmail.com', 587)
s.ehlo()
s.starttls()
s.login('my email', 'password')
for line in open('to.csv'):
    line = line.strip()
    fields = line.split(',')
    subject = 'subject'
    email = EmailMessage()
    email['Subject'] = 'subject'
    email['From'] = FROM
    email['To'] = 'to email'
    s.send_message(email)
    print('Sent to {0}'.format(fields[TO]))
    time.sleep(5)
s.quit()
How do I go about attaching the pdf file? I searched and saw one answer was using the MIMEText object to add attachments but it did not appear to work pdf.