DCP42- Sublists with specific sum

'''
This problem was asked by Google.
Given a list of integers S and a target number k, write a function that returns a subset of S that adds up to k. If such a subset cannot be made, then return null.
Integers can appear more than once in the list. You may assume all numbers in the list are positive.
For example, given S = [12, 1, 61, 5, 9, 2] and k = 24, return [12, 9, 2, 1] since it sums up to 24.
'''

from itertools import combinations

# Function 1 <----> Generate all the sublists of a list
# If list = [1, 2, 3], there are 8 sublists:
# [], [1], [2], [3], [1,2], [1,3], [2,3], [1,2,3]

def subLists(myList):
    N = len(myList)
    returnedList = list()
    returnedList.append([])
    for remaining in range(1, N):
        combinationsOfIndecesRemaining = list(combinations(list(range(N)), remaining))
        for comb in combinationsOfIndecesRemaining:
            sublist = list()
            for i in range(len(comb)):
                sublist.append(myList[comb[i]])
            returnedList.append(sublist)
    returnedList.append(myList)
    return returnedList

def solve(myList, k):
    subs = subLists(myList)
    result = list()
    flag = False
    for sub in subs:
        if sum(sub) == k:
            flag = True
            result.append(sub)
    if flag == False:
        print("There is no sublist of list " + str(myList) + ", that its elements has sum = " + str(k))
        return None
    else:
        return result

# MAIN FUNCTION
myList1 = [12, 1, 61, 5, 9, 2]
k1 = 24
myList2 = [10, 15, 3, 4, 5, 20]
k2 = 30
print("The sublists of " + str(myList1) + " that have sum = " + str(k1) + " are: " + str(solve(myList1, k1)))
print("The sublists of " + str(myList2) + " that have sum = " + str(k2) + " are: " + str(solve(myList2, k2)))