设置和检索类中属性的默认值

Question

I am using python in a google colab notebook. I created a Restaurant class and set the default value for an attribute number_served = 0. Also created an instance, new_restaurant, of the class. I get an error when I try to retrieve the attribute's value for the instance:

class Restaurant:
  """creating Restaurant class"""
  def __init__(self, name, cuisine_type):
    self.name = name
    self.cuisine_type = cuisine_type
    self.number_served = 0
  
new_restaurant = ('Secret Sky', 'coffee & sandwiches')
new_restaurant.number_served

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AttributeError Traceback (most recent call last) in () 7 8 new_restaurant = ('Secret Sky', 'coffee & sandwiches') ----> 9 new_restaurant.number_served

AttributeError: 'tuple' object has no attribute 'number_served'

Answer 1

When you create an instance of your Restaurant Class, you have to call it like so.

class Restaurant:
  """creating Restaurant class"""
  def __init__(self, name, cuisine_type):
    self.name = name
    self.cuisine_type = cuisine_type
    self.number_served = 0
  
new_restaurant = Restaurant('Secret Sky', 'coffee & sandwiches')
print(new_restaurant.number_served)