python - Flask 邮件错误 : headers = [self. 发件人，self.reply_to] + self.recipients

Question

我应该解释为什么我的问题不是重复的:TypeError: can only concatenate list (not “str”) to list

...所以它不是重复的，因为该帖子处理代码中出现的连接运算符 +；而我的问题在错误消息中有该运算符，但在代码中没有。

这是相关的 Flask 代码，我查看了回溯(如下所示)......看起来像

mail.sent(msg)

线是进攻发生的地方。我已经非常努力地解决这个问题，显然 msg 的内容有问题......但我无法弄清楚是什么。任何帮助将不胜感激!

            token = s.dumps(form.email.data, salt='email-confirm')
            subject = 'subject goes here'
            msg = Message(subject=subject, sender='recipient@email.com',
                          recipients=form.email.data)
            link = url_for('confirm_email', token=token, _external=True)
            pull_row = User.query.filter_by(email=form.email.data).first()
            firstname = pull_row.firstname
            msg.html = render_template("email_confirmationemail.html", link=link, name=firstname)
            mail.send(msg)
            return redirect(url_for('checkyouremail'))

这是回溯

2017-08-07T06:00:05.982678+00:00 app[web.1]: Traceback (most recent call last):
2017-08-07T06:00:05.982679+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 130, in handle
2017-08-07T06:00:05.982680+00:00 app[web.1]:     self.handle_request(listener, req, client, addr)
2017-08-07T06:00:05.982681+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 171, in handle_request
2017-08-07T06:00:05.982681+00:00 app[web.1]:     respiter = self.wsgi(environ, resp.start_response)
2017-08-07T06:00:05.982682+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1836, in __call__
2017-08-07T06:00:05.982682+00:00 app[web.1]:     return self.wsgi_app(environ, start_response)
2017-08-07T06:00:05.982683+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1820, in wsgi_app
2017-08-07T06:00:05.982684+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1403, in handle_exception
2017-08-07T06:00:05.982684+00:00 app[web.1]:     response = self.make_response(self.handle_exception(e))
2017-08-07T06:00:05.982685+00:00 app[web.1]:     reraise(exc_type, exc_value, tb)
2017-08-07T06:00:05.982686+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
2017-08-07T06:00:05.982686+00:00 app[web.1]:     raise value
2017-08-07T06:00:05.982687+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1817, in wsgi_app
2017-08-07T06:00:05.982688+00:00 app[web.1]:     response = self.full_dispatch_request()
2017-08-07T06:00:05.982689+00:00 app[web.1]:     rv = self.handle_user_exception(e)
2017-08-07T06:00:05.982688+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1477, in full_dispatch_request
2017-08-07T06:00:05.982690+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1381, in handle_user_exception
2017-08-07T06:00:05.982691+00:00 app[web.1]:     reraise(exc_type, exc_value, tb)
2017-08-07T06:00:05.982691+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
2017-08-07T06:00:05.982692+00:00 app[web.1]:     raise value
2017-08-07T06:00:05.982692+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1475, in full_dispatch_request
2017-08-07T06:00:05.982693+00:00 app[web.1]:     rv = self.dispatch_request()
2017-08-07T06:00:05.982694+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1461, in dispatch_request
2017-08-07T06:00:05.982695+00:00 app[web.1]:   File "/app/app.py", line 213, in login
2017-08-07T06:00:05.982695+00:00 app[web.1]:     return self.view_functions[rule.endpoint](**req.view_args)
2017-08-07T06:00:05.982696+00:00 app[web.1]:     mail.send(msg)
2017-08-07T06:00:05.982697+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_mail.py", line 492, in send
2017-08-07T06:00:05.982697+00:00 app[web.1]:     message.send(connection)
2017-08-07T06:00:05.982698+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_mail.py", line 427, in send
2017-08-07T06:00:05.982698+00:00 app[web.1]:     connection.send(self)
2017-08-07T06:00:05.982699+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_mail.py", line 181, in send
2017-08-07T06:00:05.982700+00:00 app[web.1]:     if message.has_bad_headers():
2017-08-07T06:00:05.982700+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_mail.py", line 400, in has_bad_headers
2017-08-07T06:00:05.982701+00:00 app[web.1]:     headers = [self.sender, self.reply_to] + self.recipients
2017-08-07T06:00:05.982704+00:00 app[web.1]: TypeError: can only concatenate list (not "str") to list

Answer 1

这就是解决我遇到的问题的方法。 (这是关于Message中的recipients参数)。我只有一个收件人。但我想很多收件人都在意料之中。无论如何，将我的一个收件人从字符串更改为列表就可以了。例如从

recipients=email

到

recipients=email.split()

解决了这个问题。我是 flask-mail 的新手，对于为收件人使用字符串我没有三思而后行。