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Python Python Collections (2016, retired 2019) Tuples Combo

Posted by Andrew Mlamba
Andrew Mlamba
15,642 Points

Combo

Need some help here. The grader is not passing a helpfull message for me to understand and rectify my code.

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

def combo(iterable_1, iterable_2):
    output = []
    for index in range(len(iterable_1)):
        t = iterable_1[index], iterable_2[index]
        output.append(t)
    return output

3 Answers

Umesh Ravji
Umesh Ravji
42,386 Points
Umesh Ravji
Umesh Ravji
42,386 Points

[Edit] Since the questions 'answer acceptance engine' has been changed, please see this thread: https://teamtreehouse.com/community/works-in-ide-not-in-challenge

Your answer works fine for the example provided. However, it won't work for dictionaries and sets because it won't work for collections that are not indexed based. You have to use iterators.

I doubt my way of doing it was the best, but I hope it should be enough to point you in the right direction.

def combo(a, b):
    iter_a = iter(a)
    iter_b = iter(b)
    results = []
    # use iterators and generate results here
    return results
Umesh Ravji
Umesh Ravji
42,386 Points
Umesh Ravji
Umesh Ravji
42,386 Points

Maybe it's a bug, but I'm not sure :)

Bummer! Example output: `combo('abc', 'def')` => <zip object at 0x7ffb5d63fac8>

However, this works fine:

def combo(a, b):
    return list(zip(a, b))
Alexander Davison
Alexander Davison
65,469 Points

Oops XD

I always forget to add list(). Thanks for reminding me!

~Alex

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

Adding on to Umesh's answer

:dizzy: In fact, there's an even easier way of doing this. To get rid of all this hassle, you can just use a handy-dandy function called zip.

Try this:

def combo(a, b):
    return list(zip(a, b))

You might be wondering something like "What the?... Why does Python have this useless function that I'll never use again?", however, later you'll find out that you can use zip in for loops, and, volia! You get to hold on to two variables. Wait until you see a future video and you'll get it :smile:

Finally, we convert zip into a list so that it will return what you'd expect and not a zip object. (Thanks Umesh for pointing that out :bowtie: I would've forgetten lol)

I hope this post helps as well :)

Good luck!

~Alex

EDITED: Added list() around zip()