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Python Python Collections (2016, retired 2019) Tuples Combo

Posted by Tilak Muruduru Divakar
Tilak Muruduru Divakar
6,459 Points

'combo' function challenge

I have written a function which works just fine. But I have a feeling that this can be written in a better way. Since 'tuples' are immutable, I couldn't think of a different way to create(I need to take the second item of the tuple from a different iterable) the tuple. Could someone please suggest some improvements? Is there a way to iterate over two iterables in the same loop like: for a, b in iterable1, iterable2?

combo.py 
# combo([1, 2, 3], 'abc')
# Output:
# [(1, 'a'), (2, 'b'), (3, 'c')]


def combo(iter1,iter2):
    lists_of_lists = []
    for item in iter1:
        lists_of_lists.append(list(item))
    index = 0
    for item in iter2:
        lists_of_lists[index].append(item)
        index += 1

    list_of_tuples = []
    for combo_list in lists_of_lists:
        list_of_tuples.append(tuple(combo_list))
    return list_of_tuples

2 Answers

Pete P
Pete P
7,613 Points
Pete P
Pete P
7,613 Points

Something that may help is the enumerate() function. As long as your iterables are the same length, you could do something like this:

# combo([1, 2, 3], 'abc')
# Output:
# [(1, 'a'), (2, 'b'), (3, 'c')]

def combo(iter1, iter2):
    list_of_tuples = []
    for index, item in enumerate(iter1):
        a_tuple = item, iter2[index]
        list_of_tuples.append(a_tuple)
    return list_of_tuples

Though, I'm curious to see other's ideas as well. Possibly using zip()?

Pete P
Pete P
7,613 Points
Pete P
Pete P
7,613 Points

I had to learn about the zip() function a bit. But, seems you could also do this:

def combo(iter1, iter2):
    my_tuples = zip(iter1, iter2)
    return list(my_tuples)

or even shorter

def combo(iter1, iter2):
    return list(zip(iter1, iter2))
Dustin Jasmin
Dustin Jasmin
3,156 Points

Hey, I'm currently on this challenge and my question is what does [index] do in iter2[index]?

Noor Elharty
Noor Elharty
2,630 Points
Noor Elharty
Noor Elharty
2,630 Points

i have the same question as Dustin Jasmin ? can some one clarify what index do ?