python stuck

Question

Alright, this one can be tricky but I'm sure you can do it. Create a function named combo that takes two ordered iterables. These could be tuples, lists, strings, whatever. Your function should return a list of tuples. Each tuple should hold the first item in each iterable, then the second set, then the third, and so on. Assume the iterables will be the same length. Check the code below for an example. I knew my code is not correct but I do not know how to fix it. Any hints?

https://teamtreehouse.com/library/python-collections-2/tuples/combo

def combo(first,second):
    new_tuple = []
    for a in first:
        for b in second:
            new_tuple.append((a,b))

    return(list(new_tuple))

Answer 1 · 2017-11-30T19:19:40Z

November 30, 2017 7:19pm

combo([1, 2, 3], 'abc') should return [(1, 'a'), (2, 'b'), (3, 'c')] (3 outcomes). Your code returns all possible combinations of [1, 2, 3] and ['a', 'b', 'c'] (3 * 3 = 9 outcomes). If you know the zip function, this is rather easy:

def combo(first, second):
    new_tuple = []
    for a, b in zip(first, second):
        new_tuple.append((a, b))
    return new_tuple

Or if you know list comprehension:

def combo(first, second):
    return [(x, y) for x, y in zip(first, second)]

Since new_tuple is already of list type, you don't need to wrap it with list().

If you are not familiar with zip(), you can run a for-loop controlled by the index numbers:

def combo(first,second):
    new_tuple = []
    # Get the length of the lists; doesn't matter which one, since they are equal.
    length = len(first)
    for i in range(length):
        new_tuple.append((first[i], second[i]))

    return new_tuple

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BOHAN ZHANG

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python stuck

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Idris Abdulwahab

Idris Abdulwahab