Django Tracker Python Code

# tracker/models.py
from django.db import models

class Location(models.Model):
        date = models.DateTimeField(auto_now=True, auto_now_add=True)
        latitude = models.CharField(max_length=128)
        longitude = models.CharField(max_length=128)
        accuracy = models.CharField(max_length=128)
        def __unicode__(self):
                return str(self.latitude + "," + self.longitude + "," +self.accuracy)


# tracker/views.py
from django.http import HttpResponse
from django.shortcuts import render_to_response
from DJANGOPROJECT.tracker.models import Location

def tracker(request, data):
   latitude = request.REQUEST["latitude"]
   longitude = request.REQUEST["longitude"]
   accuracy = request.REQUEST["accuracy"]
   newlocation = Location(latitude=latitude, longitude=longitude, accuracy=accuracy)
   newlocation.save()
   return HttpResponse("latitude: " + latitude + " longitude:" + longitude + " accuracy:" + accuracy, status=200, mimetype='text/plain')


def find(request):
   l = Location.objects.all().order_by("-id")[0]
   print(l.date)
   return render_to_response('tracker/find.html', {'latitude': l.latitude, 'longitude': l.longitude, 'date': l.date})

def plot(request):
   l = Location.objects.all().order_by("-id")[:20]
   centerLA = l[0].latitude
   centerLO = l[0].longitude
   return render_to_response('tracker/plot.html', {'locations': l, 'centerLA': centerLA, 'centerLO': centerLO })