sorting a ListField in mongoengine

问题

I have a model in mongoengine defined like this:

class Task(Document):

    name = StringField(required=True, unique=True)
    frequency = IntField(required=True)
    quantity = IntField()
    units = StringField()
    events = ListField(DateTimeField(default=datetime.datetime.now))

How can I get the latest event? I've tried the following to no success:

def latest(self):
    return self.events.sort()[-1]

Instead of returning the events sorted sort returns None

回答1:

You could just use the Mongoengine SortedListField instead of ListField, here is the doc

Then you could simply return self.events or its reverse if you wish as well

来源：https://stackoverflow.com/questions/45823538/sorting-a-listfield-in-mongoengine