import smtplib
 
# The below code never changes, though obviously those variables need values.
session = smtplib.SMTP('smtp.gmail.com', 587)
session.ehlo()
session.starttls()
session.login(GMAIL_USERNAME, GMAIL_PASSWORD)

headers = "\r\n".join(["from: " + GMAIL_USERNAME,
            "subject: " + email_subject
            "to: " + recipient,
            "mime-version: 1.0",
            "content-type: text/html"])
 
# body_of_email can be plaintext or html!          
content = headers + "\r\n\r\n" + body_of_email
session.sendmail(GMAIL_USERNAME, recipient, content)