用python写一段代码，flask 异步发送带附件的邮件

以下是用 Python 编写的 Flask 异步发送带附件的邮件的代码：

from flask import Flask, render_template, request
from flask_mail import Mail, Message
from threading import Thread

app = Flask(__name__)
app.config.update(
    DEBUG=True,
    MAIL_SERVER='smtp.gmail.com',
    MAIL_PORT=587,
    MAIL_USE_TLS=True,
    MAIL_USERNAME='your_email@gmail.com',
    MAIL_PASSWORD='your_password'
)

mail = Mail(app)

def send_async_email(app, msg):
    with app.app_context():
        mail.send(msg)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/send_email', methods=['POST'])
def send_email():
    recipient = request.form['recipient']
    subject = request.form['subject']
    body = request.form['body']
    attachment = request.files['attachment']

    msg = Message(subject, sender='your_email@gmail.com', recipients=[recipient])
    msg.body = body
    msg.attach(attachment.filename, attachment.read(), attachment.content_type)

    thr = Thread(target=send_async_email, args=[app, msg])
    thr.start()

    return 'Email sent!'

if __name__ == '__main__':
    app.run()

请注意，这只是一个示例代码，您需要将其适当修改以适应您的需求。