Return all possible combinations of two lists-CodePudding

I've tried to return all the possible combinations of two given lists using class the combination will have to consist of one element from each list. I can do until the length of the second list is 1. But after increasing the length, I don't get the expected output.

as an example the code is

class IceCreamMachine:

    def __init__(self, ingredients, toppings):
        self.ingredients = ingredients
        self.toppings = toppings
        
    def scoops(self):
        IceCreamList = []
        for i in range(len(self.ingredients)):
            IceCreamList.append([self.ingredients[i], self.toppings[i%len(self.toppings)]])
        
        return IceCreamList
        
machine = IceCreamMachine(["vanilla", "chocolate"], ["chocolate sauce"])

print(machine.scoops())

it returns the expected output which is [['vanilla', 'chocolate sauce'], ['chocolate', 'chocolate sauce']] but whenever I tend to increase the element of the second list it shows an incorrect answer. Can anyone suggest me how to solve the problem?

CodePudding user response：

using itertools.product

import itertools

class IceCreamMachine:
    def __init__(self, ingredients, toppings):
        self.ingredients = ingredients
        self.toppings = toppings
        
    def scoops(self):
      return list(itertools.product(self.ingredients,self.toppings))
        
machine = IceCreamMachine(["vanilla", "chocolate"], ["chocolate sauce","banana sauce"])
print(machine.scoops())

output

[('vanilla', 'chocolate sauce'), ('vanilla', 'banana sauce'), ('chocolate', 'chocolate sauce'), ('chocolate', 'banana sauce')]

CodePudding user response：

I think this can be done by using two for-loop:

def scoops(self):
    IceCreamList = []
    for i in range(len(self.ingredients)):
        for j in range(len(self.toppings)):
            IceCreamList.append([self.ingredients[i], self.toppings[j]])
    
    return IceCreamList

use "for [variable] in [list]" can make the code looks simpler

def scoops(self):
    IceCreamList = []
    for i in self.ingredients:
        for j in self.toppings:
            IceCreamList.append([i,j])
    
    return IceCreamList

if you want to have the combination with more than one option, the code will be more complicated then this...