Based on this example I made following function:
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
def send_email(host, port, user, pwd, recipients, subject, body, html=None, from_=None):
    """ copied and adapted from
        https://stackoverflow.com/questions/10147455/how-to-send-an-email-with-gmail-as-provider-using-python#12424439
    returns None if all ok, but if problem then returns exception object
    """
    PORT_LIST = (25, 587, 465)
    FROM = from_ if from_ else user 
    TO = recipients if isinstance(recipients, (list, tuple)) else [recipients]
    SUBJECT = subject
    TEXT = body.encode("utf8") if isinstance(body, unicode) else body
    HTML = html.encode("utf8") if isinstance(html, unicode) else html
    if not html:
        # Prepare actual message
        message = """From: %s\nTo: %s\nSubject: %s\n\n%s
        """ % (FROM, ", ".join(TO), SUBJECT, TEXT)
    else:
                # https://stackoverflow.com/questions/882712/sending-html-email-using-python#882770
        msg = MIMEMultipart('alternative')
        msg['Subject'] = SUBJECT
        msg['From'] = FROM
        msg['To'] = ", ".join(TO)
        # Record the MIME types of both parts - text/plain and text/html.
        # utf-8 -> https://stackoverflow.com/questions/5910104/python-how-to-send-utf-8-e-mail#5910530
        part1 = MIMEText(TEXT, 'plain', "utf-8")
        part2 = MIMEText(HTML, 'html', "utf-8")
        # Attach parts into message container.
        # According to RFC 2046, the last part of a multipart message, in this case
        # the HTML message, is best and preferred.
        msg.attach(part1)
        msg.attach(part2)
        message = msg.as_string()
    try:
        if port not in PORT_LIST: 
            raise Exception("Port %s not one of %s" % (port, PORT_LIST))
        if port in (465,):
            server = smtplib.SMTP_SSL(host, port)
        else:
            server = smtplib.SMTP(host, port)
        # optional
        server.ehlo()
        if port in (587,): 
            server.starttls()
        server.login(user, pwd)
        server.sendmail(FROM, TO, message)
        server.close()
        # logger.info("SENT_EMAIL to %s: %s" % (recipients, subject))
    except Exception, ex:
        return ex
    return None
if you pass only body then plain text mail will be sent, but if you pass html argument along with body argument, html email will be sent (with fallback to text content for email clients that don't support html/mime types).
Example usage:
ex = send_email(
      host        = 'smtp.gmail.com'
   #, port        = 465 # OK
    , port        = 587  #OK
    , user        = "[email protected]"
    , pwd         = "xxx"
    , from_       = '[email protected]'
    , recipients  = ['[email protected]']
    , subject     = "Test from python"
    , body        = "Test from python - body"
    )
if ex: 
    print("Mail sending failed: %s" % ex)
else:
    print("OK - mail sent"
Btw. If you want to use gmail as testing or production SMTP server, 
enable temp or permanent access to less secured apps: