send json from appengine with python to google charts api

get_daily_log_per_user_in_team.py

from collections import namedtuple                                                                                                 
class AdminLogsByTeamHandler(AdminHandler): # get                                                                               
  @admin_required
  def get(self, team_id):
    team_key = ndb.Key(Team, int(team_id))                                                                                         

    Quantity = namedtuple("Quantity", ["date", "account"])
    resolution_by_day = {}
    logs = Log.query(Log.team == team_key).fetch()                                                         
    for log in logs:                                                                                                               
      date = log.created.date().isoformat()                                                                                        
      account = log.sender.id()                                                                                                    
      q = Quantity(date=date, account=account)
      if q in resolution_by_day:
        resolution_by_day[q] += 1
      else:   
        resolution_by_day[q] = 1                                                                                                   

    # make 2d array                                                                                                                
    date_set = set(d for d, a in resolution_by_day)                                                                                
    account_set = set(a for d, a in resolution_by_day)
    result = []

    # make header
    header = ['Date']
    for account in account_set:                                                                                                    
      a = Account.get_by_id(int(account))
      name = a.name if a is not None else account
      header.append(name)
    result.append(header)

    # make rows
    for date in date_set:                                                                                                          
      row = [date]
      for account in account_set:
        q = Quantity(date=date, account=account)                                                                                   
        if q in resolution_by_day:                                                                                                 
          row.append(resolution_by_day[q])                                                                                         
        else :
          row.append(0)
      result.append(row)                                                                                                   
    self.response_object(result)