如何在python 3.6.2中向自动邮件(smtplib)添加更改内容?

我想给自己发封信。如何将内容更改为可变文本而不是静态文本?

import smtplib
import random
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

#food dictionary 

food = random.choice([spaghetti, pizza])

def mail():

    email_user = 'me'
    email_send = ['no1','no2']

    msg = MIMEMultipart()
    msg['From'] = email_user
    msg['To'] = ','.join(email_send)
    msg['Subject'] = 'food for the week!'

    body = 'why can't I get my new content in here?!'

这就是部分 (body=...) 我想我有麻烦了。我怎样才能把“食物”从 random.choice() part并没有收到错误消息?还是有更好的方法?

msg.attach(MIMEText(body,'plain'))
text = msg.as_string()
mail =smtplib.SMTP("smtp.gmail.com", 587)
mail.ehlo()
mail.starttls()
mail.login(email_user,"pwd")
mail.sendmail(email_user,email_send, text)
mail.close()
mail()