I have this function where i am using models ‘Start’ and ‘End’ that contain fields latitude and longitude.. and I am trying to match them with a field called elements that I am using subscript to extract the start_id and end_id and match them with ‘Start’ and ‘End’
The function in question that is giving me a subscript error is:
def dispatch(request): events = Event.objects.filter(description="Dispatch").values("element") starts = Start.objects.all() ends = End.objects.all() # subscript error fixed d_starts = { s.start_id: s for s in start } # subscript error fixed d_ends = { c.end_id: c for c in end } d_start_end_ids = [ { 'start': d_starts[e['element'][52:58]], 'end': d_ends[e['element'][69:75]] } for e in events ] for d in d_start_end_ids: # Error is here data = {'[%s, %s] -> [%s, %s]' % (d['start']['latitude'], d['start']['longitude'], d['end']['latitude'], d['end']['longitude'])} JsonResponse(data)
I am getting an error saying:
line 33, in dispatch_data data = '[%s, %s] -> [%s, %s]' % (d['start']['latitude'], d['start']['longitude'], d['end']['latitude'], d['end']['longitude']) TypeError: 'Start' object is not subscriptable]
My Start model is:
class Start(models.Model): start_id = models.CharField(primary_key=True, max_length=100) name = models.CharField(max_length=150) latitude = models.FloatField(null=True) longitude = models.FloatField(null=True)
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Answer
Keep in mind that in your for loop the variables d['start']
and d['end']
each contain an instance of the Start
model. To manipulate the fields of an instance you should use the dot .
(you should use subscript when dealing with subscriptable objects – see What does it mean if a Python object is “subscriptable” or not?):
data = {'[%s, %s] -> [%s, %s]' % (d['start'].latitude, d['start'].longitude, d['end'].latitude, d['end'].longitude)}