old_contents: class Place(object):
  
      def __init__(self, name='', address='', phone='', category=''):
          self.name = name
          self.address = address
          self.phone = phone
          self.category = category
  
      def get_name(self):
          return self.name
  
      def get_address(self):
          return self.address
  
      def get_phone(self):
          return self.phone
  
      def get_category(self):
          return self.category
new_contents: class Place(object):
  
      def __init__(self, name='', address='', phone='', category=None):
          self.name = name
          self.address = address
          self.phone = phone
          self.category = category
  
      def get_name(self):
          return self.name
  
      def get_address(self):
          return self.address
  
      def get_phone(self):
          return self.phone
  
      def get_category(self):
          return self.category
  
      def get_category_string(self):
          if self.category == 3:
              return 'Nhà hàng'
          if self.category == 4:
              return 'Cà phê/Kem'
          if self.category == 5:
              return 'Quán ăn'
          return 'Undefined ' + str(self.category)
  
subject: Add get category string