Specifications for the Pizza class.

The implementation of this class is almost simplistic! All of the methods $($except two$)$ are only single code statements. My class implementation is only $30$ lines of code.

Class attributes

Remember that class members do not have a "self" prefix and are accessed with the class name and the dot operator.

$1.$ Valid sizes for pizza contained in a collection at the class level.

You get to figure out the type of collection to store the sizes below.

Valid sizes are small, medium, large and x$-$large.

$2.$ Another class level collection having the prices for each valid size.

You get to decide on the type of collection to store the prices below.

Prices are small: $$6\mathrm{.}49,$ medium: $$8\mathrm{.}49,$ large: $$10\mathrm{.}49,$ x$-$large: $$13\mathrm{.}49.$

Constructor

Instance methods have an implicit first argument "self".

$3.$ A constructor that takes a default size of medium and topping of a list of cheese that does the following:

a$.$ Set the first argument size to the instance attribute size. Size must be verified. This can be done by setting the size property.

b$.$ Creates an instance attribute a list with the second argument. If the second argument is missing, a single cheese topping is inserted in the list.

Instance methods

Instance methods have an implicit first argument "self".

$4.$ A method that takes an argument of type list of strings. It adds topping to the list of pizza toppings.

$5.$ Implement the $\_\_$str$\_\_()$ method to return a formatted string. Examine the output from the test harness for clues on how to implement this method.

Instance Properties

Instance properties have an implicit first argument "self".

$6.$ A property that returns the price of the pizza.

a$.$ Price is based on the size as well as the number of toppings.

See spec#$2$ for cost based on size. Each topping cost an additional $$0\mathrm{.}50$ each.

$7.$ A property that returns the size of the pizza.

$8.$ A property that sets the size of the pizza.

a$.$ Size must be verified. A ValueError exception is raised if the size is invalid.

Instance Attributes

All of the following Instance attributes are initialized in the constructor from the values of the argument. Notice the $\_\_$ prefix to make is private.

$9.\_\_$size is a str that stores the size of this object. This is initialized in the constructor. It is mutated by the property in #$8.$ It is returned in #$7.$ It is used in #$6$ to calculate the cost of the pizza.

$10.\_\_$toppings a list of string that represents the toppings for this object. This is initialized in the constructor. It is mutated in the add$()$ method and is used in #$6$ to calculate the cost of the pizza.