How to use a class function on class objects in a list in Python?

Question

I want to create a tool that allows a user to input a list of restaurant details to be stored and printed back out when complete.

My code follows:

#Create restaurant class with restaurant object and describe_restaurant function

class restaurant:
    def __init__(self, n, restaurant_name, cuisine_type):
        self.n = n
        self.restaurant_name = restaurant_name
        self.cuisine_type = cuisine_type

     def describe_restaurant(self):
        print("{} serves {}".format(restaurant.restaurant_name, restaurant.cuisine_type))

#localplaces will contain the restaurant objects

localplaces = []
n = len(localplaces)
active = True

while active:
    localplaces.append(restaurant(n, input("Restaurant Name: "), input("Cuisine type: ")))
    repeat = input("Do you want to add another item?: ")
    if repeat.strip().lower() in ["n", "no"]:
        active = False
    else:
        while repeat.strip().lower() not in ['y', 'yes', 'n', 'no']:
            repeat = input("Add another item? [y/n]: ")

#loop through localplaces printing the object info as defined by the

for restaurant in localplaces:
    print("\n" + restaurant.describe_restaurant().format)

I get the following error when running this code (including my input):

Restaurant Name: bobs
Cuisine type: burgers
Do you want to add another item?: n
bobs serves burgers
Traceback (most recent call last):
  File "C:/Users/nicholl/PycharmProjects/untitled/Coordinates.py", line 24, in <module>
    print("\n" + restaurant.describe_restaurant().format)
AttributeError: 'NoneType' object has no attribute 'format'

Meanwhile if I remove .format from my for loop (including my input):

Restaurant Name: bobs
Cuisine type: burgers
Do you want to add another item?: n
bobs serves burgers
Traceback (most recent call last):
  File "C:/Users/user/PycharmProjects/Test/Test11111c.py", line 24, in <module>
    print("\n" + restaurant.describe_restaurant())
TypeError: can only concatenate str (not "NoneType") to str

Which confused me by giving me what I assume is a returned describe_restaurant() but if I input a second restaurant I receive the same error, excluding the second restaurant but it will still return the first restaurant as above.

Using Python 3.7 in PyCharm, let me know if I need to clarify anything.

Answer 1

You're referencing restaurant in this function, but it is a reference to the class , which doesn't have restaurant_name or cuisine_type attributes:

def describe_restaurant(self):
    print("{} serves {}".format(restaurant.restaurant_name, restaurant.cuisine_type))

Instead, use self , which will be a reference to the object itself:

def describe_restaurant(self):
    print("{} serves {}".format(self.restaurant_name, self.cuisine_type))

A couple of other stylistic tips:

• Name your class Restaurant instead of restaurant (see PEP 8 )
• Name your method describe instead of describe_restaurant ; that method is part of your class and the context should make it clear that it relates to restaurants