This is how my JSON data looks like
{"id": 50, "first_digit": "2", "second_digit": "1", "calculate": "Addition"}
I want to add extra data "result":"3" to my JSON
this is my view
def calc(request):
if request.method == 'POST':
first_number = request.POST['first number']
second_number = request.POST['second number']
operation = request.POST['operation']
result = do_calc(operation, first_number, second_number)
# how to pass the result to my tempelate
value = Calculation.objects.create(
first_digit=first_number,
second_digit=second_number,
calculate=operation
)
data = model_to_dict(value)
return JsonResponse(data)
Can anyone help me with it
Presumably the output of model_to_dict() is a dict. So you can simply add your value to that dict:
data = model_to_dict(value)
data['result'] = result
return JsonResponse(data)
Related
I have a simple JSON and want to convert it to DynamoDB JSON. Is there any easy way to do that?
If you mean JsonString to Dynamodb Map, you can use boto3.
Here is the example.
import boto3
import json
json_string = '{"key1": 1, "key2": "value"}'
json_obj = json.loads(json_string)
dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('test-table')
table.put_item(Item={'pk': 'pk-value', 'map': json_obj})
If you just want to update the while Map attribute, you can use just JSON format the same as put_item.
json_string = '{"key1": 2, "key2": "value2"}'
json_obj = json.loads(json_string2)
rsp = table.update_item(
Key={'pk': 'pk-value'},
AttributeUpdates={'map': {'Value': json_obj2, 'Action': 'PUT'}}
)
However, If you want to update only specific nested attribute, you need to use UpdateExpression. For example, the below is code to update only key1 attribute to 'value3'.
nested_json_string = '{"nested": "key3"}'
nested_json_obj = json.loads(nested_json_string)
rsp = table.update_item(
Key={'pk': 'pk-value'},
UpdateExpression='SET #map.#key1 = :val3',
ExpressionAttributeNames={'#map': 'map', '#key1': 'key1'},
ExpressionAttributeValues={':val3': nested_json_obj}
)
I know this is an old question, but I came across it and the accepted answer didn't help me (it seems to suggest that you can feed boto3 with plain JSON, but it didn't work for me) and the library mentioned in the comments didn't help me either.
What did work for me was using the serializer/deserializer from boto3.dynamodb.types, basically as suggested by this answer on a very similar topic.
from boto3.dynamodb.types import TypeSerializer, TypeDeserializer
import json
serializer = TypeSerializer()
deserializer = TypeDeserializer()
# for building a DynamoDB JSON from a Python object
def serialize(item):
serialized_item = serializer.serialize(vars(item) if hasattr(item, '__dict__') else item)
return item if 'M' not in serialized_item else serialized_item['M']
# for building a plain JSON from a DynamoDB JSON
def deserialize(dynamodb_json_string):
return deserializer.deserialize({'M': dynamodb_json_string})
class MyItem:
def __init__(self, some_string_value=None, some_numeric_value=None):
self.my_key = some_string_value
self.my_other_key = some_numeric_value
def __str__(self):
return json.dumps(self, default=lambda x: x.__dict__)
if __name__ == '__main__':
my_classy_item = MyItem("my_string_value", 5)
my_string_item = json.loads('{"my_key": "my_string_value", "my_other_key" : 5}')
print(serialize(my_classy_item))
print(serialize(my_string_item))
My python code reads the excel sheet and converts it into a json file output. I have a column in the excel sheet, where the values are either "Planned" or "Unplanned".
1)In the json output, I want the Planned to be replaced with "1" and Unplanned to be replaced with "2" without changing anything in the excel file.
2)In the output I dont want "data" to appear.
3)In the excel, my Start time column value is like this "2018-11-16 08:00:00". I want the output to be "2018-11-16T08:00:00Z". Currently i am getting some garbage value.
Below is my code.
import xlrd, json, time, pytz, requests
from os import sys
from datetime import datetime, timedelta
from collections import OrderedDict
def json_from_excel():
excel_file = 'test.xlsx'
jsonfile = open('ExceltoJSON.json', 'w')
data = []
datestr = str(datetime.now().date())
loaddata = OrderedDict()
workbook = xlrd.open_workbook(excel_file)
worksheet = workbook.sheet_by_name('OMS-GX Data Extraction')
sheet = workbook.sheet_by_index(0)
for j in range(0, 6):
for i in range(1, 40):
temp = {}
temp["requestedStart"] = (sheet.cell_value(i,0)) #Start Time
temp["requestedComplete"] = (sheet.cell_value(i, 1)) #End Time
temp["location"] = (sheet.cell_value(i, 3)) #Station
temp["equipment"] = (sheet.cell_value(i, 4)) #Device Name
temp["switchOrderTypeID"] = (sheet.cell_value(i, 5)) #Outage Type
data.append(temp)
loaddata['data'] = data
json.dump(loaddata, jsonfile, indent=3, sort_keys=False)
jsonfile.write('\n')
return loaddata
if __name__ == '__main__':
data = json_from_excel()
Below is my sample output:
{
"data": [
{
"requestedStart": testtime,
"requestedComplete": testtime,
"location": "testlocation",
"equipment": "testequipment",
"switchOrderTypeID": "Planned"
},
{
"requestedStart": testtime,
"requestedComplete": testtime,
"location": "testlocation",
"equipment": "testequipment",
"switchOrderTypeID": "Unplanned"
}
]
}
Answer to the 1st question:
You may use conditional assignment.
temp["switchOrderTypeID"] = (1 if sheet.cell_value(i, 5) == "Planned" else 0)
Answer to the 2nd question:
Use loaddata = data which will be an array of the jsons without data as json key.
Answer to 3rd question:
from dateutil.parser import parse
t = "2018-11-16 08:00:00"
parse(t).strftime("%Y-%m-%dT%H:%M:%SZ")
I'm looking for a way to convert list of JSON object into an approximate SQLAlchemy model. Is there any implementation?
This is what I did in one of my projects to convert json input from an http request to an sqlalchemy model dynamically:
if request.method == "POST" or request.method == "PUT":
data = request.get_json(force=True)
print("data:", data)
try:
TableClass = models.get_class_by_tablename(table_name)
if TableClass == None: raise Exception("Table not found: %s" % table_name)
if request.method == "POST": #insert data
object = TableClass(**data)
dbsession.add(object)
dbsession.commit()
else: #update data
object = dbsession.query(TableClass).filter_by(**{"id":id}).first()
if object == None: raise Exception("No data found.")
#object.update(**data)
for key in data.keys():
setattr(object, key, data[key])
#dbsession.add(object)
dbsession.commit()
return jsonify({
"status": "success",
"id": object.id,
})
except Exception as e:
return jsonify({
"status": "error",
"error": str(e),
})
data is the variable that gets converted from json input to the usual python dictionary. Then **data is passed as argument for the instance creation of sqlalchemy table class.
I've decided to migrate my Django project to work with SqlAlchemy instead of Django ORM and I'm trying to serialize my SqlAlchemy output to a JSON which contains column names.
In Django I had the following code:
logs = Log.objects.values('log_timestamp', 'message', 'exception', 'level__level', 'job_info__job_name', 'machine', 'user', 'job_report__id').filter(job_info__app_id = app_id).order_by('-time_added')[:1]
logs = json.dumps(list(logs), default=views_utils.default_json_serializer)
print(logs)
and here an output example (contains column names):
[{"user": "user", "level__level": "INFO", "message": "this is a message", "log_timestamp": null, "job_info__job_name": "MongoDB_Maintenance", "exception": "exception details", "machine": "machine", "job_report__id": 65}]
Here is my SqlAlchemy code:
res = session.query(func.DATETIME(LogObj.time_added), LogObj.message, LogObj.exception, LogLevelObj.level, LogObj.machine, LogObj.user).\
join(PeriodicJobInfoObj, LogLevelObj, LogObj,aliased=True).\
filter(PeriodicJobInfoObj.app_id == app_id).\
order_by(desc(LogObj.time_added))[:1]
res = json.dumps(res, default=views_utils.default_json_serializer)
print(res)
The output does not contain column names:
[["2015-09-28 15:36:33", "this is a message", "exception details", "CRITICAL", "machine", "user"]]
default_json_serializer code:
def default_json_serializer(obj):
"""Default JSON serializer."""
import calendar, datetime
if isinstance(obj, datetime.datetime):
if obj.utcoffset() is not None:
obj = obj - obj.utcoffset()
millis = int(
calendar.timegm(obj.timetuple()) * 1000 +
obj.microsecond / 1000
)
return millis
How can I achieve similar output like Django does?
(working with Python 3.4.2)
I have managed to do it this way:
def alchemyencoder(obj):
if isinstance(obj, datetime.date):
return obj.isoformat()
elif isinstance(obj, decimal.Decimal):
return float(obj)
I use the above encoder when retrieving records in following way:
row = conn.execute(Model.__table__.select())
d = json.dumps([dict(r) for r in row], default=alchemyencoder)
d = json.JSONDecoder().decode(d)
print(d)
I 'm doing something like this:
def prods = Product.executeQuery("select category.id,category.name, avg(competition1Price), avg(competition2Price), avg(onlineCompetitionPrice) from Product group by category.id")
def output = [[:]]
prods.each { result ->
def prod = ['category_id':result[0],'category_name':result[1],'Competition1Price':result[2],'competition2Price':result[3],'onlineCompetitionPrice':result[4]]
output << prod
}
render output as JSON
the output I'm getting is something like:
[{},{"category_id":1,"category_name":"Colchones y","Competition1Price":1657.4784,"competition2Price":2071.5,"onlineCompetitionPrice":1242.5}]
What I want is:
something like this..
{collection:[{"category_id":"1","category_name":"Colchones y",so on...]}
can someone please help..
How to manipulate the format of json data..
If that's the format you want, you'll need to do:
def prods = Product.executeQuery("select category.id,category.name, avg(competition1Price), avg(competition2Price), avg(onlineCompetitionPrice) from Product group by category.id")
def output = [collection:[]]
prods.each { result ->
def prod = ['category_id':result[0],'category_name':result[1],'Competition1Price':result[2],'competition2Price':result[3],'onlineCompetitionPrice':result[4]]
output.collection << prod
}
render output as JSON
Or (arguably neater):
def prods = Product.executeQuery("select category.id,category.name, avg(competition1Price), avg(competition2Price), avg(onlineCompetitionPrice) from Product group by category.id")
def prodlist = prods.collect { result ->
[ 'category_id': result[0],
'category_name': result[1],
'Competition1Price':result[2],
'competition2Price':result[3],
'onlineCompetitionPrice':result[4] ]
}
render [ collection: prodlist ] as JSON