如何不从func返回两种不同的类型？

Question

I have the following method:

async def check_for_pending_status(self, alert_id):
    alert_comments = await get_comments(alert_id)
    for comm in alert_comments:
        if comm['status'] == COMMENT_STATUS.PENDING.value:
            return True, comm.get('email')
    return False

That's how I use it:

is_pending_exists, email = await self.check_for_pending_status(comment.alert_id)
if is_pending_exists:
    comment['status'] = COMMENT_STATUS.PENDING
    if email is not None:
        comment['email'] = email

I'm new in python. I don't know is it good to return in one method tuple - True, comm.get('email') and just one value - False .

Is there any way to improve algorithm and rewrite it in the more pythonic way (I mean rewrite loop iteration)?

Answer 1

Provided that comm.get('email') can not be None itself, you could just return the e-mail of the pending comment, if any, or None otherwise.

async def check_for_pending_status(self, alert_id):
    alert_comments = await get_comments(alert_id)
    for comm in alert_comments:
        if comm['status'] == COMMENT_STATUS.PENDING.value:
            return comm.get('email')
    return None

And then check like this:

pending_email = await self.check_for_pending_status(comment.alert_id)
if pending_email is not None:
    comment['status'] = COMMENT_STATUS.PENDING
    comment['email'] = email

You could also rewrite this using next , but whether that's better might be a matter of taste:

async def check_for_pending_status(self, alert_id):
    alert_comments = await get_comments(alert_id)
    return next((comm.get('email') for comm in alert_comments 
                 if comm['status'] == COMMENT_STATUS.PENDING.value),
                None)

Answer 2

It is perfectly fine to return a tuple from a method.

If you don't like the fact you return only False you can always return False, None