text: import json
  
  s = '{"fires": null, "expenses": 14.99, "sales": [{"revenue": 100,
  "day:": "Monday"}, {"revenue": 200, "day": "Tuesday"}, {"day":
  "Wednesday", "holiday": true}]}'
  
  print(sum([day for day in data['sales'] if 'revenue' in day.keys()]))
  
  
  