Part B

Here is solution code for the Recipe class from last time. To simplify the code, we have removed the input checking in the $\_$init $\_$ method, as well

as the $\_$ method.

In $[]$: class Recipe:

def $($self$,$ title, ingredients, directions$)$:

self.title $=$ title

self.ingredients $=$ ingredients

self.directions $=$ directions

def$\_$rmul$\_($self$,$ multiplier$)$:

multiplied$\_$ingredients $=\{$key : multiplier$*$val for key, val in self.ingredients.items$()\}$

return Recipe$($self$.$title, multiplied$\_$ingredients, self.directions$)$

Now, implement subtraction in which the first argument is a Pantry and the second argument is a Recipe $.$ The relevant magic method for this is

called $\_(),$ and should be implemented in the Pantry class. Here's how subtraction my$\_$pantry $-$ my$\_$recipe should work:

You may assume that my$\_$pantry and my$\_$recipe are valid instances of their class. In particular, all quantities of ingredients are positive numbers

$($ int s or float s$).$

If all keys from my$\_$recipe. ingredients are present in my$\_$pantry, and if they all have values smaller than their values in my$\_$pantry, then the

result of my$\_$pantry $-$ my$\_$recipe is a new Pantry object in which the values corresponding to the keys have been reduced by the quantity in

my$\_$recipe.

If a key is present in my$\_$pantry but not in my$\_$recipe, then it is treated as though it is present in my$\_$pantry with value $0.$

For now, you can assume that the conditions of clause $2.$ are met, and that subtraction should therefore "work." That is$,$ you can assume that you have

enough of all ingredients in the pantry to make the recipe. For example, with my$\_$pantry from Part $A,$

title $=$ "cookies"

ingredients

"flour $($grams$)"$: $400,$

"butter $($grams$)"$ : $200,$

"salt $($arams$)"$ : $10.$