Django 2.3:很难让表单发送带有附件的电子邮件。不确定应如何使用FormView处理/处理文件

from django import forms
from django.core.mail import EmailMessage
from django.views.generic.edit import FormView
from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase
from email import encoders
import smtplib

class MyForm(forms.Form):
    subject = forms.CharField()
    message = forms.CharField(widget=forms.Textarea)
    attachment = forms.FileField()

class MyFormView(FormView):
    form_class = MyForm
    template_name = 'my_template.html'
    success_url = '/success/'

    def form_valid(self, form):
        # 获取表单数据
        subject = form.cleaned_data['subject']
        message = form.cleaned_data['message']
        attachment = self.request.FILES['attachment']

        # 构建邮件对象
        email = MIMEMultipart()
        email['Subject'] = subject
        email['From'] = 'sender@example.com'
        email['To'] = 'recipient@example.com'

        # 添加文本内容
        email.attach(MIMEText(message, 'plain'))

        # 添加附件
        part = MIMEBase('application', 'octet-stream')
        part.set_payload(attachment.read())
        encoders.encode_base64(part)
        part.add_header('Content-Disposition', f'attachment; filename="{attachment.name}"')
        email.attach(part)

        # 发送邮件
        with smtplib.SMTP('smtp.example.com', 587) as smtp:
            smtp.login('username', 'password')
            smtp.sendmail('sender@example.com', 'recipient@example.com', email.as_string())

        return super().form_valid(form)