How to transform JavaScript filter function to Django Python?

Question

I have the following filter function on JavaScript and I need to do the same on Django.

This is my JavaScript function:

absentAttendees() {     
      return this.meeting.attendees.filter((element) => this.timeAttendees(element.user.id) <= 0 || (element.absent && this.timeAttendees(element.user.id) <= 0));
    }

timeAttendees(user) {
      let timeUser = 0
      this.meeting.meeting_times.forEach((time) => {
        if (time.user.id === user) {
          timeUser = timeUser + time.time
        }
      })

      return timeUser
    }

Here is what I have so far on Django, but it tells me that the object I'm passing doesn't have the attribute 'user'

timeList = filter(timeAttendees, meeting.attendees.all())
def timeAttendees(item):
            timeUser = 0
            
            for time in time_list:
                if(time.user.id == item.user.id):
                    timeUser = timeUser + time.time
                
            return timeUser

meeting.attendees refers to the following model:

meeting = models.ForeignKey(
Meeting, related_name="attendees", on_delete=models.CASCADE
)
user = models.ForeignKey(
    User, related_name="attendee", on_delete=models.CASCADE, null=True, blank=True
)
idd = models.CharField(max_length=255)
organizer = models.BooleanField(default=False)
absent = models.BooleanField(default=True)
verified = models.BooleanField(default=False)

you forgot to save the value of meeting.attendees.all().filter(timeAttendees > 0) in time_list i think . if not what is time_list — Rvector
– Rvector, Commented Sep 16, 2021 at 17:14
Right forgot about that part, although my main problem is that item on the function is not carrying the properties from the model — Gamoxion
– Gamoxion, Commented Sep 16, 2021 at 17:17
What is item ? an user or a structure of user or another model instance? — Rvector
– Rvector, Commented Sep 16, 2021 at 17:21
item would be the attendees model, which has properties and a user model inside — Gamoxion
– Gamoxion, Commented Sep 16, 2021 at 17:23
Can you edit and include the definition of every variable that is being used? — Rustam Garayev
– Rustam Garayev, Commented Sep 16, 2021 at 17:24

Rustam Garayev · Accepted Answer · 2021-09-16 17:55:13Z

1

Assuming meeting is some Meeting object, and item is valid object here is how you can replicate timeAttendees function:

meeting = <Meeting_object>
def get_time_attendees(item):
    global meeting
    return sum([interval.time for interval in meeting.meeting_times
                if interval.user.id == item.user.id])

Above function returns total time that user appeared in meeting_times. To get absent attendees, filter() and map() could do the job:

def get_absent_attendees(meeting):
    attendees = meeting.attendees.all()
    return list(filter(lambda x: x <= 0, list(map(get_time_attendees, attendees))))

list(map(get_time_attendees, attendees)) calls get_time_attendees function in every attendees object and converts the result into a list. Then with filter, you grab the ones with attendance time less than zero.

answered Sep 16, 2021 at 17:55

Rustam Garayev

2,6921 gold badge11 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Gamoxion Over a year ago

Perfect, does exactly what I needed.

Collectives™ on Stack Overflow

How to transform JavaScript filter function to Django Python?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related