Object has no attribute 'distance' - GeoDjango

Question

I am referring to the answer in the question listed below as I am trying to run a query that gets the closest object to a given point in my django application. My django version is 1.9.2.

How to return a record with the lowest distance from a point using geodjango?

In my view I am passing in a Zipcode and using GeoPy to get the location and lat/long.

from django.contrib.gis.geos import *
from django.contrib.gis.measure import D
from geopy.geocoders import Nominatim

geolocator = Nominatim()

zipcode = self.request.query_params.get('zipcode', None)
distance_m = 20000

if zipcode is not None:
    location = geolocator.geocode(zipcode, timeout=None)
    origin = Point((location.latitude, location.longitude))

    queryset = Chapter.objects.filter(location__distance_lte=(origin, D(m=distance_m))).distance(origin).order_by('distance')[:1][0] 
    return queryset

The Chapter model has a field called location which is a point field.

from django.contrib.gis.db import models

class Chapter(models.Model):
    name = models.CharField(max_length=500)
    school = models.ForeignKey(School)
    verification = models.CharField(max_length=50)
    address1 = models.TextField()
    address2 = models.TextField(null=True, blank=True)
    city = models.TextField()
    state = models.TextField()
    zipcode = models.CharField(max_length=5)
    location = models.PointField(srid=4326, null=True, blank=True)
    is_school = models.BooleanField(default=False)
    is_association = models.BooleanField(default=False)
    authorized = models.NullBooleanField(default=False)
    stripe_account_active = models.NullBooleanField(default=False)

    def __unicode__(self):
        return self.name

    def get_nickname(self):
        return self.school.nickname

I get the following error when this executes:

AttributeError: 'QuerySet' object has no attribute 'distance'

Edit--

When I try to get the distance using the alternate method in the questions above I get a different error which makes me think there is something wrong with my model.

point = Chapter.objects.get(name='Chapter of the Year').location
distance_m = 20000

for chapter in Chapter.objects.distance(point):
    print(chapter.name, chapter.distance)

Error:

'Manager' object has no attribute 'distance'

score 6 · Answer 1 · answered May 06 '17 at 10:37

6

Got this to work

Chapter.objects.filter(location__distance_lte=(origin, D(m=distance_m))).annotate(distance=Distance('location', origin)).order_by('distance')[:1][0]

answered May 06 '17 at 10:37

Brandon Mitchell

185
1
9

5

From where did you import `Distance`? – Brett Jackson Jan 26 '18 at 20:12
3

@BrettJackson `from django.contrib.gis.db.models.functions import Distance` – jmq Aug 17 '18 at 22:58

Prakhar Trivedi · Accepted Answer · 2017-05-06T09:54:06.407

2

As written in this line :

queryset = Chapter.objects.filter(location__distance_lte = (origin, D(m=distance_m))).distance(origin).order_by('distance')[:1][0]

You are ordering the result by distance but that is not a field/attribute in Chapter model. I think what you want is order by location__distance, so the actual filter query should be:

queryset = Chapter.objects.filter(location__distance_lte= (origin, D(m=distance_m))).distance(origin).order_by('location__distance')[:1][0]

Also this line is totally incorrect :

for chapter in Chapter.objects.distance(point):

Because here, distance is not a method like filter or get. It should be something like that :

point = Chapter.objects.get(name='Chapter of the Year')
distance_m = 20000

for chapter in Chapter.objects.filter(id = point.id ):
    print(chapter.name, chapter.location.distance)

edited May 06 '17 at 09:54

answered May 06 '17 at 09:13

Prakhar Trivedi

8,218
3
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1

I just tried this and its still not working. I just added some additional context to the question after trying to loop through and get the distance for each instance. – Brandon Mitchell May 06 '17 at 09:34
@BrandonMitchell The problem with both conditions are the same. **Chapter** model does not have a field/ attribute named **distance**. – Prakhar Trivedi May 06 '17 at 09:41
@BrandonMitchell Please add the code of model **Chapter** also in the question. That will help in solving the problem. – Prakhar Trivedi May 06 '17 at 09:42
@BrandonMitchell You can notice from the question from where you are taking help, that answer does not mention anything about this method. It was Op's mistake in that question also. – Prakhar Trivedi May 06 '17 at 09:56
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/143564/discussion-between-prakhar-trivedi-and-brandon-mitchell). – Prakhar Trivedi May 06 '17 at 10:11
Still trying to get the queryset to return the closest location. – Brandon Mitchell May 06 '17 at 10:30

Object has no attribute 'distance' - GeoDjango

2 Answers2