CODEWITHSUNDEEP
pythonlistclass
George
George

Reputation: 4674

Create a list of objects

I am working on a little text base resultant game, but I am having troubling creating this list of Food, I want to put all my Food (either Burger, or Hotdog) in listOfFood. In my example I only included two, but they are all "base" on food.

Later then I will iterate through my listOfFood to do something. I abstracted my code to ask question (because it has too many lines, and the other information is not related to it).

class Food():
    def __init__(self):
        self.name = 'Food'

class HotDog(Food):
    def __init__(self):
        Food.__init__(self)

class Burger(Food):
    def __init__(self):
        Food.__init__(self)

def createFoodList(myOrders):
    # A list that contain all the food (either Burger or Hotdog)
    listOfFood = []

    # Depend what is the type of the food, create that many food object
    # and then append it to the list of food
    if myOrders[0][0] == 'HotDog':
        for number in myOrder[0][1]:
            listOfFood.append(HotDot())
    if myOrders[0][1] == 'Burger':
        for number in myOrder[0][1]:
            listOfFood.append(Burger())

    return listOfFood


todayOrders = [['HotDog', 10], ['Burger', 5]]
print(createFoodList(todayOrders))

I wonder if I can use list comprehension or similar method to make my createFoodList function better? Because my idea is to have many different kind of Food, so if I can return this list of food, base on todayOrders list ['type of food', count] and return [food, food, food.. ]. The way I am doing right now is really complicated and long (I have a feeling this is not the right way).

Thank you very much.

Edit: Besides the list comprehension, what can I do to replace the if statements in createFoodList? It is decide on the [[food, count], [food, count]..], and I create that food and append it to my list.

Upvotes: 0

Views: 393

Answers (2)

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 799580

foodmap = {'HotDog': HotDog, 'Burger': Burger}

print [foodmap[f]() for (f, c) in todayOrders for x in range(c)]

foodmap[f] evaluates to either HotDog or Burger (these are classes - not class names, the classes themselves). Calling someclass() creates an instance of soemclass and passes no arguments when calling someclass.__init__. Hence foodmap[f]() combines both of these - it looks up the class in foodmap and uses the class to create an instance of that class.

Upvotes: 4

Abhijit
Abhijit

Reputation: 63787

This looks more like a factory pattern. You can try the following solution

>>> class Food():
    def __init__(self,name='Food'):
        self.name = name
    def __repr__(self):
    return self.name

>>> class HotDog(Food):
    def __init__(self):
        Food.__init__(self,'HotDog')


>>> class Burger(Food):
    def __init__(self):
        Food.__init__(self,'Burger')

>>> def createFoodList(myOrders):
    return [apply(order[0]) for order in myOrders for i in xrange(0,order[1]) if callable(order[0])]

>>> todayOrders = [[HotDog, 10], [Burger, 5]]
>>> print(createFoodList(todayOrders))
[HotDog, HotDog, HotDog, HotDog, HotDog, HotDog, HotDog, HotDog, HotDog, HotDog, Burger, Burger, Burger, Burger, Burger]

Upvotes: 2

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