python - local variable 'server_name' referenced before assignment in django view -

i creating django app stores servers in database. servers come list via third party app. app needs go through list add servers aren't in database , delete in database aren't in list. however, when try deletion part of requirements keep getting referenced before assignment error part of code states server.objects.filter(server_name in i) not sure if can server_name in i way have done playing around it. have got error when doing server.objects.filter(server_name=i) (which know should work). can help?

from django.shortcuts import render django.http import httpresponse .models import server hive.cloud.pyraxhelpers.pyraxhelpers import list_hostnames django.core.exceptions import objectdoesnotexist  def server_home(request):     return render(request, 'templates/index.html', {})  def server(request):     server_name = server.objects.get(server_name)     in list_hostnames():         print "going through list"         if server.objects.filter(server_name=i).exists():             print "server exists skip"         else:             if server.objects.filter(server_name in i):                 print "add new server"                server_name = server.objects.create(server_name=i)                 return httpresponse("added")             else:                 print "delete"                 return httpresponse("deleted") return httpresponse("worked") 

model

class server(models.model):     server_name = models.charfield(primary_key=true, max_length=250)     renewal_date = models.datefield('expiry date', null=false, default=timezone.now)     deletion_date = models.datefield('deletion date', null=false, default=timezone.now)     def __unicode__(self):         return self.server_name 

you're getting error because you're referencing server_name variable before assignment, error says.

the problem in line:

server_name = server.objects.get(server_name)

what should second server_name variable contain? python doesn't know.

it looks want add argument call, def server(request, server_name). make sure change urls.py.