报'NoneType' object has no attribute 'policy'如何解决？

Question

#-*-coding:gbk-*-
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

class SendMail:
    def send_mail(self,report_file,mail_subjet,mail_user,mail_to,mail_pwd,mail_host,text):
        # 读取测试报告内容
        with open(report_file,'r') as f:
                content = f.read()
        f.close()
        #添加邮件内容
        msg=MIMEMultipart('mixed')
        msg_txt=msg.attach(MIMEText(text,'plain','utf-8'))
        msg.attach(msg_txt)
        # 添加附件
        msg_attachment = MIMEText(content, 'html', 'utf-8')
        msg_attachment["content-Type"]='application/octet-stream'
        msg_attachment["Content-Disposition"]='"attachment;filename={0}"'.format(report_file)
        msg.attach(msg_attachment)
        #把Subject，From，To，Date添加到MIMEText对象或者MIMEMultipart对象中，邮件中才会显示主题，发件人，收件人，时间
        msg['Subject'] = mail_subjet
        msg['From'] = mail_user
        msg['To'] = ';'.join(mail_to)
        try:
            # 连接邮件服务器
            s=smtplib.SMTP(mail_host,25)
            # 登陆
            s.login(mail_user,mail_pwd)
            # 发送邮件
            s.sendmail(mail_user,mail_to,msg.as_string())
        except Exception as e:
            print ("邮件发送失败 ", e)
        finally:
            s.quit()

Answer 1

你把你的try...except，去掉，看看报错到底在哪行，是哪个函数还是数据出错了