I have this view
def view_involved_people(request):
schedule = request.POST['schedule']
query = Schedule.objects.get(pk=schedule)
serialized = serializers.serialize('json', query)
data = {'people': serialized}
return JsonResponse(data)
It displays that the object is not iterable. I think it is because I am only getting one instance of the object. However, how can I prevent this error and get this data from the view?
I have tried using .filter() but when I call data.attribute_name, it does not display the value
You have to use filter in you case:
def view_involved_people(request):
schedule = request.POST['schedule']
query = Schedule.objects.filter(pk=schedule)
serialized = serializers.serialize('json', query)
data = {'people': serialized}
return JsonResponse(data)
Related
From a Django app, I am able to consume data from a separate Restful API, but what about filtering? Below returns all books and its data. But what if I want to grab only books by an author, date, etc.? I want to pass an author's name parameter, e.g. .../authors-name or /?author=name and return only those in the json response. Is this possible?
views.py
def get_books(request):
response = requests.get('http://localhost:8090/book/list/').json()
return render(request, 'books.html', {'response':response})
So is there a way to filter like a model object?
I can think of three ways of doing this:
Python's filter could be used with a bit of additional code.
QueryableList, which is the closest to an ORM for lists I've seen.
query-filter, which takes a more functional approach.
1. Build-in filter function
You can write a function that returns functions that tell you whether a list element is a match and the pass the generated function into filter.
def filter_pred_factory(**kwargs):
def predicate(item):
for key, value in kwargs.items():
if key not in item or item[key] != value:
return False
return True
return predicate
def get_books(request):
books_data = requests.get('http://localhost:8090/book/list/').json()
pred = filter_pred_factory(**request.GET)
data_filter = filter(pred, books_data)
# data_filter is cast to a list as a precaution
# because it is a filter object,
# which can only be iterated through once before it's exhausted.
filtered_data = list(data_filter)
return render(request, 'books.html', {'books': filtered_data})
2. QueryableList
QueryableList would achieve the same as the above, with some extra features. As well as /books?isbn=1933988673, you could use queries like /books?longDescription__icontains=linux. You can find other functionality here
from QueryableList import QueryableListDicts
def get_books(request):
books_data = requests.get('http://localhost:8090/book/list/').json()
queryable_books = QueryableListDicts(books_data)
filtered_data = queryable_books.filter(**request.GET)
return render(request, 'books.html', {'books':filtered_data})
3. query-filter
query-filter has similar features but doesn't copy the object-orient approach of an ORM.
from query_filter import q_filter, q_items
def get_books(request):
books_data = requests.get('http://localhost:8090/book/list/').json()
data_filter = q_filter(books_data, q_items(**request.GET))
# filtered_data is cast to a list as a precaution
# because q_filter returns a filter object,
# which can only be iterated through once before it's exhausted.
filtered_data = list(data_filter)
return render(request, 'books.html', {'books': filtered_data})
It's worth mentioning that I wrote query-filter.
This code seems to work fine when I used Django console and just print it.
reference = FloodHazard.objects.filter(hazard='High')
ids = reference.values_list('id', flat=True)
for myid in ids:
getgeom = FloodHazard.objects.get(id=myid).geom
response = BuildingStructure.objects.filter(geom__intersects=getgeom).values(
'brgy_locat').annotate(counthigh=Count('brgy_locat'))
print response
I was able to show all the values, but when using HttpResponse, it returns an empty set. What is the proper way of returning JSON data from a queryset? So far, tried this:
reference = FloodHazard.objects.filter(hazard='High')
ids = reference.values_list('id', flat=True)
response = {}
for myid in ids:
getgeom = FloodHazard.objects.get(id=myid).geom
response['high'] = BuildingStructure.objects.filter(geom__intersects=getgeom).values(
'brgy_locat').annotate(counthigh=Count('brgy_locat'))
json_post = ujson.dumps(list(response))
return HttpResponse(json_post, content_type='application/json')
There is no much sense in your code. You assign all querysets to the single key in the response dict. You should use a list for this purpose:
As far as I understand the code should be something like this:
response = []
for myid in ids:
getgeom = FloodHazard.objects.get(id=myid).geom
response.extend(BuildingStructure.objects.filter(geom__intersects=getgeom)
.values('brgy_locat')
.annotate(counthigh=Count('brgy_locat')))
json_post = ujson.dumps(response)
If you want to return a hazard level as well as the list of buildings then you can return a dict:
json_post = ujson.dumps({'hazard': 'high', 'buildings': response})
I have a sort function on a project I'm working on, where users can create a sort query of all the assets they're working on. When they get the results of their query, I want them to be able to download a .csv of all the objects in the query.
However, when I try to store the query results in a session, I get an error that the results are not JSON serializable. If I don't try to store the query results then the sort runs fine, but then export button won't work since the query results haven't been stored.
In my views:
def sort(request, project_id=1):
thisuser = request.user
project = Project.objects.get(id=project_id)
if Project.objects.filter(Q(created_by=thisuser) | Q(access__give_access_to=thisuser), id=project_id).exists():
permission = 1
else:
permission = None
if Asset.objects.filter(project__id=project_id, unique_id=1):
assets = 1
else:
assets = None
if request.POST:
if request.POST.get('date_start') and request.POST.get('date_end'):
date_start = datetime.strptime(request.POST['date_start'], '%m/%d/%Y')
date_end = datetime.strptime(request.POST['date_end'], '%m/%d/%Y')
q_date = Q(date_produced__range=[date_start, date_end])
else:
q_date = Q(date_produced__isnull=False) | Q(date_produced__isnull=True)
text_fields = {
'asset_type': request.POST.get('asset_type'),
'description': request.POST.get('description'),
'master_status': request.POST.get('master_status'),
'location': request.POST.get('location'),
'file_location': request.POST.get('file_location'),
'footage_format': request.POST.get('footage_format'),
'footage_region': request.POST.get('footage_region'),
'footage_type': request.POST.get('footage_type'),
'footage_fps': request.POST.get('footage_fps'),
'footage_url': request.POST.get('footage_url'),
'stills_credit': request.POST.get('stills_credit'),
'stills_url': request.POST.get('stills_url'),
'music_format': request.POST.get('music_format'),
'music_credit': request.POST.get('music_credit'),
'music_url': request.POST.get('music_url'),
'license_type': request.POST.get('license_type'),
'source': request.POST.get('source'),
'source_contact': request.POST.get('source_contact'),
'source_email': request.POST.get('source_email'),
'source_id': request.POST.get('source_id'),
'source_phone': request.POST.get('source_phone'),
'source_fax': request.POST.get('source_fax'),
'source_address': request.POST.get('source_address'),
'credit_language': request.POST.get('source_language'),
'cost': request.POST.get('cost'),
'cost_model': request.POST.get('cost_model'),
'total_cost': request.POST.get('total_cost'),
'notes': request.POST.get('notes')
}
boolean_fields = {
'used_in_film': request.POST.get('used_in_film'),
'footage_blackandwhite': request.POST.get('footage_blackandwhite'),
'footage_color': request.POST.get('footage_color'),
'footage_sepia': request.POST.get('footage_sepia'),
'stills_blackandwhite': request.POST.get('stills_blackandwhite'),
'stills_color': request.POST.get('stills_color'),
'stills_sepia': request.POST.get('stills_sepia'),
'license_obtained': request.POST.get('license_obtained')
}
q_objects = Q()
for field, value in text_fields.iteritems():
if value:
q_objects = Q(**{field+'__contains': value})
q_boolean = Q()
for field, value in boolean_fields.iteritems():
if value:
q_boolean |= Q(**{field: True})
query_results = Asset.objects.filter(q_date, q_objects, q_boolean)
list(query_results)
request.session['query_results'] = list(query_results)
args = {'query_results': query_results, 'thisuser': thisuser, 'project': project, 'assets': assets}
args.update(csrf(request))
args['query_results'] = query_results
return render_to_response('sort_results.html', args)
else:
args = {'thisuser': thisuser, 'project': project, 'assets': assets}
args.update(csrf(request))
return render_to_response('sort.html', args)
This is the line: "request.session['query_results'] = list(query_results)" that causes it to fail. It also fails if it's "request.session['query_results'] = query_results"
The reason of this error is that you try to assign list on model instances to session. Model instance cannot be serialized to JSON. If you want to pass list of instances of Asset model to session you can do in that way:
query_results = Asset.objects.values('id','name').filter(q_date, q_objects, q_boolean)
You can list necessary model fields in values()
In that case you will have list of dictionaries, not instances. And this list may be assigned to session. But you cannot operate with this dictionaries like instances of class Assign, i.e. you cannot call class methods and so on.
In the following example I can return the record if I already know it's sequence number that was returned when I inserted the data.
But how do I return all the data that has been added by different devices?
import boto
mykin = boto.connect_kinesis(aws_access_key_id='access_key',
aws_secret_access_key='secret_key')
myput = mykin.put_record(stream_name='mytest', data='abcdefghij',
partition_key='parti11', b64_encode=True)
myiterator = mykin.get_shard_iterator(stream_name='mytest',
shard_id='shardId-000000000000',
shard_iterator_type='AT_SEQUENCE_NUMBER',
starting_sequence_number=
myput['SequenceNumber'])
mykin.get_records(shard_iterator=myiterator['ShardIterator'])
in your producer:
kinesis = boto.kinesis.connect_to_region('us-east-1', aws_access_key_id, aws_secret_access_key)
response = kinesis.describe_stream('stream_name')
shard_id = response['StreamDescription']['Shards'][0]['ShardId']
response = kinesis.get_shard_iterator('stream_name', shard_id, 'TRIM_HORIZON')
I am try to perform a RAW SQL query in django. I am having some trouble getting the fetchall result to output a list of the distinct items in a column.
So I am hoping to get a list of all the items in a column.
class TableObject (object):
def __init__ (self, Kingdom):
SQL_str_Table = "SELECT DISTINCT column_title FROM sql_table"
cursor.execute(SQL_str_Table, [])
listOfReturns = cursor.fetchall()
for each in listOfReturns:
item = each
when I try a print out of "item" I get:
"bound method TableObject.write of mysite.forms.veiws.TableObject object at 0x03E5EE70"
So my question is how do I get the fetchall result into a list.
If you want to get a flat list of only column_title's then you can do this:
listOfReturns = cursor.fetchall()
listOfReturns_flat = [i for i in listOfReturns if i[0]] #remove empty results if any