input: Write a function to design a web server in Python using the Flask framework that serves a JSON object containing the current temperature for a city based on the city name given in the request. 
  
  assert get_temp({'city': 'London'})=={'temperature': 280.32}
  assert get_temp({'city': 'New York'})=={'temperature': 290.15}
  assert get_temp({'city': 'Tokyo'})=={'temperature': 285.78}
  assert get_temp({'city': 'Paris'})=={'temperature': 283.54}
  assert get_temp({'city': 'Sydney'})=={'temperature': 295.21}
output: def get_temp(request):
      city = request['city']
      temp_data = {
          'London': 280.32,
          'New York': 290.15,
          'Tokyo': 285.78,
          'Paris': 283.54,
          'Sydney': 295.21
      }
      return {'temperature': temp_data.get(city, None)}