code: import os, sys
  import json
  import os.path
  import numpy
  
  class DemandProfile:
      def __init__(self):
          cwd = os.getcwd()
          self.fname = cwd + '/demand-profile.json'
          
      def get_data(self):
          demand={}
          with open(self.fname) as demand_info:
              demand = json.load(demand_info)
          return demand
  
      def calculate_total_demand(self):
          data = self.get_data()
          total_energy_data=[]
          num=0
          total_demand = numpy.zeros(24)
          for i in data:
              value = i[str(1+num)]["Circulation Pump"]+i[str(1+num)]["Dish Washer"]+i[str(1+num)]["Freezer"]+i[str(1+num)]["Washing Machine"]
              total_demand[num] = value
              num+=1
          return total_demand
  
  #sample object
  #sample = DemandProfile()
  #print(sample.calculate_total_demand())
apis: numpy.zeros